diff --git a/rswag-specs/lib/rswag/specs/request_factory.rb b/rswag-specs/lib/rswag/specs/request_factory.rb
index daae7da..6f7cf96 100644
--- a/rswag-specs/lib/rswag/specs/request_factory.rb
+++ b/rswag-specs/lib/rswag/specs/request_factory.rb
@@ -27,6 +27,7 @@ module Rswag
       end
 
       def build_body(example)
+        return build_form_data(example) if parameters_in(:formData).present?
         body_parameter = parameters_in(:body).first
         body_parameter.nil? ? '' : example.send(body_parameter[:name]).to_json
       end
@@ -93,6 +94,10 @@ module Rswag
           "#{name}=#{value.join(',')}" # csv is default
         end
       end
+
+      def build_form_data(example)
+        Hash[parameters_in(:formData).map { |p| [p[:name][/^\w+[^\[]/, 0], example.send(p[:name][/^\w+[^\[]/, 0])] }]
+      end
     end
   end
 end
diff --git a/rswag-specs/spec/rswag/specs/request_factory_spec.rb b/rswag-specs/spec/rswag/specs/request_factory_spec.rb
index c6791b1..1ba46eb 100644
--- a/rswag-specs/spec/rswag/specs/request_factory_spec.rb
+++ b/rswag-specs/spec/rswag/specs/request_factory_spec.rb
@@ -158,6 +158,17 @@ module Rswag
           end
         end
 
+        context "'formData' parameter" do
+          before do
+            api_metadata[:operation][:parameters] << { name: 'comment', in: :formData, type: 'string' }
+            allow(example).to receive(:comment).and_return('Some comment')
+          end
+
+          it 'returns the example value as a hash' do
+            expect(body).to eq({"comment" => "Some comment"})
+          end
+        end
+
         context "referenced 'body' parameter" do
           before do
             api_metadata[:operation][:parameters] << { '$ref' => '#/parameters/comment' }
@@ -171,6 +182,20 @@ module Rswag
             expect(body).to eq("{\"text\":\"Some comment\"}")
           end
         end
+
+        context "referenced 'formData' parameter" do
+          before do
+            api_metadata[:operation][:parameters] << { '$ref' => '#/parameters/comment' }
+            global_metadata[:parameters] = {
+              'comment' => { name: 'comment', in: :formData, type: 'string' }
+            }
+            allow(example).to receive(:comment).and_return('Some comment')
+          end
+
+          it 'returns the example value as a json string' do
+            expect(body).to eq({"comment" => "Some comment"})
+          end
+        end
       end
 
       describe '#build_headers' do
diff --git a/test-app/app/controllers/blogs_controller.rb b/test-app/app/controllers/blogs_controller.rb
index 261d718..90b7102 100644
--- a/test-app/app/controllers/blogs_controller.rb
+++ b/test-app/app/controllers/blogs_controller.rb
@@ -4,10 +4,19 @@ class BlogsController < ApplicationController
 
   # POST /blogs
   def create
-    @blog = Blog.create(params.require(:blog).permit(:title, :content))
+    thumbnail = save_uploaded_file(params[:blog][:thumbnail])
+    @blog = Blog.create(params.require(:blog).permit(:title, :content).merge(:thumbnail => thumbnail))
     respond_with @blog
   end
 
+  # Put /blogs/1
+  def upload
+    @blog = Blog.find_by_id(params[:id])
+    return head :not_found if @blog.nil?
+    @blog.thumbnail = save_uploaded_file params[:file]
+    head @blog.save ? :ok : :unprocsessible_entity
+  end
+
   # GET /blogs
   def index
     @blogs = Blog.all
@@ -24,4 +33,14 @@ class BlogsController < ApplicationController
     respond_with @blog, status: :not_found and return unless @blog
     respond_with @blog
   end
+
+  private
+
+  def save_uploaded_file(field)
+    return if field.nil?
+    require 'fileutils'
+    file = File.join('tmp', field.original_filename)
+    FileUtils.cp field.tempfile.path, file
+    field.original_filename
+  end
 end
diff --git a/test-app/app/models/blog.rb b/test-app/app/models/blog.rb
index 51b0795..de7f8b5 100644
--- a/test-app/app/models/blog.rb
+++ b/test-app/app/models/blog.rb
@@ -5,7 +5,8 @@ class Blog < ActiveRecord::Base
     {
       id: id,
       title: title,
-      content: content
+      content: content,
+      thumbnail: thumbnail
     }
   end
 end
diff --git a/test-app/config/routes.rb b/test-app/config/routes.rb
index ed6b6ed..d0c4170 100644
--- a/test-app/config/routes.rb
+++ b/test-app/config/routes.rb
@@ -1,5 +1,6 @@
 TestApp::Application.routes.draw do
   resources :blogs, defaults: { :format => :json }
+  put '/blogs/:id/upload', to: 'blogs#upload'
 
   mount Rswag::Api::Engine => 'api-docs'
   mount Rswag::Ui::Engine => 'api-docs'
diff --git a/test-app/db/migrate/20160218212104_create_blogs.rb b/test-app/db/migrate/20160218212104_create_blogs.rb
index 81d9813..db86f36 100644
--- a/test-app/db/migrate/20160218212104_create_blogs.rb
+++ b/test-app/db/migrate/20160218212104_create_blogs.rb
@@ -3,6 +3,7 @@ class CreateBlogs < ActiveRecord::Migration
     create_table :blogs do |t|
       t.string :title
       t.text :content
+      t.string :thumbnail
 
       t.timestamps
     end
diff --git a/test-app/db/schema.rb b/test-app/db/schema.rb
index 082bb8d..d7ecc76 100644
--- a/test-app/db/schema.rb
+++ b/test-app/db/schema.rb
@@ -16,6 +16,7 @@ ActiveRecord::Schema.define(:version => 20160218212104) do
   create_table "blogs", :force => true do |t|
     t.string   "title"
     t.text     "content"
+    t.string   "thumbnail"
     t.datetime "created_at", :null => false
     t.datetime "updated_at", :null => false
   end
diff --git a/test-app/spec/fixtures/thumbnail.png b/test-app/spec/fixtures/thumbnail.png
new file mode 100644
index 0000000..5790d6c
Binary files /dev/null and b/test-app/spec/fixtures/thumbnail.png differ
diff --git a/test-app/spec/integration/blogs_spec.rb b/test-app/spec/integration/blogs_spec.rb
index 0ae884c..9ef08a9 100644
--- a/test-app/spec/integration/blogs_spec.rb
+++ b/test-app/spec/integration/blogs_spec.rb
@@ -8,11 +8,13 @@ describe 'Blogs API', type: :request, swagger_doc: 'v1/swagger.json' do
       tags 'Blogs'
       description 'Creates a new blog from provided data'
       operationId 'createBlog'
-      consumes 'application/json'
-      parameter name: :blog, :in => :body, schema: { '$ref' => '#/definitions/blog' }
+      consumes 'application/x-www-form-urlencoded'
+      parameter name: 'blog[title]', :in => :formData, type: 'string'
+      parameter name: 'blog[content]', :in => :formData, type: 'string'
+      parameter name: 'blog[thumbnail]', :in => :formData, type: 'file'
 
       response '201', 'blog created' do
-        let(:blog) { { title: 'foo', content: 'bar' } }
+        let(:blog) { { title: 'foo', content: 'bar', thumbnail: Rack::Test::UploadedFile.new(Rails.root.join("spec/fixtures/thumbnail.png")) } }
         run_test!
       end
 
@@ -34,7 +36,7 @@ describe 'Blogs API', type: :request, swagger_doc: 'v1/swagger.json' do
       response '200', 'success' do
         schema type: 'array', items: { '$ref' => '#/definitions/blog' }
 
-        let(:keywords) { 'foo bar' }
+        let(:keywords) { 'foo+bar' }
         run_test!
       end
     end
@@ -59,10 +61,11 @@ describe 'Blogs API', type: :request, swagger_doc: 'v1/swagger.json' do
         examples 'application/json' => {
             id: 1,
             title: 'Hello world!',
-            content: 'Hello world and hello universe. Thank you all very much!!!'
+            content: 'Hello world and hello universe. Thank you all very much!!!',
+            thumbnail: "thumbnail.png"
           }
 
-        let(:blog) { Blog.create(title: 'foo', content: 'bar') }
+        let(:blog) { Blog.create(title: 'foo', content: 'bar', thumbnail: 'thumbnail.png') }
         let(:id) { blog.id }
         run_test!
       end
@@ -73,4 +76,29 @@ describe 'Blogs API', type: :request, swagger_doc: 'v1/swagger.json' do
       end
     end
   end
+
+  path '/blogs/{id}/upload' do
+    parameter name: :id, :in => :path, :type => :string
+
+    put 'upload a blog thumbnail' do
+      tags 'Blogs'
+      description 'Upload a thumbnail for specific blog by id'
+      operationId 'uploadThumbnailBlog'
+      consumes 'application/x-www-form-urlencoded'
+      parameter name: :file, :in => :formData, :type => 'file', required: true
+
+      response '200', 'blog updated' do
+        let(:blog) { Blog.create(title: 'foo', content: 'bar') }
+        let(:id) { blog.id }
+        let(:file) { Rack::Test::UploadedFile.new(Rails.root.join("spec/fixtures/thumbnail.png")) }
+        run_test!
+      end
+
+      response '404', 'blog not found' do
+        let(:id) { 'invalid' }
+        let(:file) { Rack::Test::UploadedFile.new(Rails.root.join("spec/fixtures/thumbnail.png")) }
+        run_test!
+      end
+    end
+  end
 end
diff --git a/test-app/spec/spec_helper.rb b/test-app/spec/spec_helper.rb
index 8f698be..d20f071 100644
--- a/test-app/spec/spec_helper.rb
+++ b/test-app/spec/spec_helper.rb
@@ -47,6 +47,10 @@ RSpec.configure do |config|
   # triggering implicit auto-inclusion in groups with matching metadata.
   config.shared_context_metadata_behavior = :apply_to_host_groups
 
+  config.after(:suite) do
+    File.delete("#{Rails.root}/tmp/thumbnail.png") if File.file?("#{Rails.root}/tmp/thumbnail.png")
+  end
+
 # The settings below are suggested to provide a good initial experience
 # with RSpec, but feel free to customize to your heart's content.
 =begin
diff --git a/test-app/spec/swagger_helper.rb b/test-app/spec/swagger_helper.rb
index a3b76b4..d98442a 100644
--- a/test-app/spec/swagger_helper.rb
+++ b/test-app/spec/swagger_helper.rb
@@ -39,9 +39,10 @@ RSpec.configure do |config|
           properties: {
             id: { type: 'integer' },
             title: { type: 'string' },
-            content: { type: 'string' }
+            content: { type: 'string' },
+            thumbnail: { type: 'string'}
           },
-          required: [ 'id', 'title', 'content' ]
+          required: [ 'id', 'title', 'content', 'thumbnail' ]
         }
       },
       securityDefinitions: {
diff --git a/test-app/swagger/v1/swagger.json b/test-app/swagger/v1/swagger.json
index acbcd1e..f74398a 100644
--- a/test-app/swagger/v1/swagger.json
+++ b/test-app/swagger/v1/swagger.json
@@ -14,15 +14,23 @@
         "description": "Creates a new blog from provided data",
         "operationId": "createBlog",
         "consumes": [
-          "application/json"
+          "application/x-www-form-urlencoded"
         ],
         "parameters": [
           {
-            "name": "blog",
-            "in": "body",
-            "schema": {
-              "$ref": "#/definitions/blog"
-            }
+            "name": "blog[title]",
+            "in": "formData",
+            "type": "string"
+          },
+          {
+            "name": "blog[content]",
+            "in": "formData",
+            "type": "string"
+          },
+          {
+            "name": "blog[thumbnail]",
+            "in": "formData",
+            "type": "file"
           }
         ],
         "responses": {
@@ -107,7 +115,8 @@
               "application/json": {
                 "id": 1,
                 "title": "Hello world!",
-                "content": "Hello world and hello universe. Thank you all very much!!!"
+                "content": "Hello world and hello universe. Thank you all very much!!!",
+                "thumbnail": "thumbnail.png"
               }
             }
           },
@@ -116,6 +125,43 @@
           }
         }
       }
+    },
+    "/blogs/{id}/upload": {
+      "parameters": [
+        {
+          "name": "id",
+          "in": "path",
+          "type": "string",
+          "required": true
+        }
+      ],
+      "put": {
+        "summary": "upload a blog thumbnail",
+        "tags": [
+          "Blogs"
+        ],
+        "description": "Upload a thumbnail for specific blog by id",
+        "operationId": "uploadThumbnailBlog",
+        "consumes": [
+          "application/x-www-form-urlencoded"
+        ],
+        "parameters": [
+          {
+            "name": "file",
+            "in": "formData",
+            "type": "file",
+            "required": true
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "blog updated"
+          },
+          "404": {
+            "description": "blog not found"
+          }
+        }
+      }
     }
   },
   "definitions": {
@@ -147,12 +193,16 @@
         },
         "content": {
           "type": "string"
+        },
+        "thumbnail": {
+          "type": "string"
         }
       },
       "required": [
         "id",
         "title",
-        "content"
+        "content",
+        "thumbnail"
       ]
     }
   },