diff --git a/modules/openapi-generator/src/main/resources/csharp/libraries/generichost/api.mustache b/modules/openapi-generator/src/main/resources/csharp/libraries/generichost/api.mustache
index f75235833fbe..c8855162a1ee 100644
--- a/modules/openapi-generator/src/main/resources/csharp/libraries/generichost/api.mustache
+++ b/modules/openapi-generator/src/main/resources/csharp/libraries/generichost/api.mustache
@@ -477,8 +477,11 @@ namespace {{packageName}}.{{apiPackage}}
 
                     List<KeyValuePair<string{{nrt?}}, string{{nrt?}}>> formParameterLocalVars = new List<KeyValuePair<string{{nrt?}}, string{{nrt?}}>>();
 
-                    multipartContentLocalVar.Add(new FormUrlEncodedContent(formParameterLocalVars));{{/-first}}{{^isFile}}{{#required}}
+                    multipartContentLocalVar.Add(new FormUrlEncodedContent(formParameterLocalVars));
 
+                    {{/-first}}
+                    {{^isFile}}
+                    {{#required}}
                     formParameterLocalVars.Add(new KeyValuePair<string{{nrt?}}, string{{nrt?}}>("{{baseName}}", ClientUtils.ParameterToString({{paramName}})));
 
                     {{/required}}
@@ -490,13 +493,41 @@ namespace {{packageName}}.{{apiPackage}}
                     {{/isFile}}
                     {{#isFile}}
                     {{#required}}
+                    {{#isContainer}}
+                    foreach (global::System.IO.Stream streamLocalVar in {{paramName}})
+                    {
+                        global::System.Net.Http.StreamContent streamContentLocalVar = new global::System.Net.Http.StreamContent(streamLocalVar);
+                        streamContentLocalVar.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
+                        {
+                            Name = "\"files\"",
+                            FileName = "\"file\""
+                        };
+                        multipartContentLocalVar.Add(streamContentLocalVar);
+                    }
+
+                    {{/isContainer}}
+                    {{^isContainer}}
                     multipartContentLocalVar.Add(new StreamContent({{paramName}}));
 
+                    {{/isContainer}}
                     {{/required}}
                     {{^required}}
                     if ({{paramName}}.IsSet)
+                    {{#isContainer}}
+                        foreach (global::System.IO.Stream streamLocalVar in {{paramName}}.Value)
+                        {
+                            var streamContentLocalVar = new global::System.Net.Http.StreamContent(file);
+                            streamContentLocalVar.Headers.ContentDisposition = new ContentDispositionHeaderValue("form-data")
+                            {
+                                Name = "\"files\"",
+                                FileName = "\"file\""
+                            };
+                            multipartContentLocalVar.Add(streamContentLocalVar);
+                        }
+                    {{/isContainer}}
+                    {{^isContainer}}
                         multipartContentLocalVar.Add(new StreamContent({{paramName}}.Value));
-
+                    {{/isContainer}}
                     {{/required}}
                     {{/isFile}}
                     {{/formParams}}
diff --git a/modules/openapi-generator/src/test/resources/3_0/csharp/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml b/modules/openapi-generator/src/test/resources/3_0/csharp/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
index 1c9e901ad0dd..90a134dfed53 100644
--- a/modules/openapi-generator/src/test/resources/3_0/csharp/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
+++ b/modules/openapi-generator/src/test/resources/3_0/csharp/petstore-with-fake-endpoints-models-for-testing-with-http-signature.yaml
@@ -17,6 +17,36 @@ tags:
   - name: user
     description: Operations about user
 paths:
+  /upload:
+    post:
+      summary: Upload multiple files
+      operationId: uploadFiles
+      requestBody:
+        required: true
+        content:
+          multipart/form-data:
+            schema:
+              type: object
+              properties:
+                files:
+                  type: array
+                  items:
+                    type: string
+                    format: binary
+              required:
+                - files
+      responses:
+        '200':
+          description: Files uploaded successfully
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  message:
+                    type: string
+                  fileCount:
+                    type: integer
   /roles/report:
     get:
       responses: