diff --git a/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultGenerator.java b/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultGenerator.java
index 0ad05b0762b..34a8534c6cd 100644
--- a/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultGenerator.java
+++ b/modules/swagger-codegen/src/main/java/io/swagger/codegen/DefaultGenerator.java
@@ -430,6 +430,12 @@ public class DefaultGenerator extends AbstractGenerator implements Generator {
         }
 
         operations.put("imports", imports);
+
+        // add a flag to indicate whether there's any {{import}}
+        if (imports.size() > 0) {
+            operations.put("hasImport", true);
+        }
+
         config.postProcessOperations(operations);
         if (objs.size() > 0) {
             List<CodegenOperation> os = (List<CodegenOperation>) objs.get("operation");
diff --git a/modules/swagger-codegen/src/main/resources/csharp/api.mustache b/modules/swagger-codegen/src/main/resources/csharp/api.mustache
index 3ede1c783a1..47fcc1bef1d 100644
--- a/modules/swagger-codegen/src/main/resources/csharp/api.mustache
+++ b/modules/swagger-codegen/src/main/resources/csharp/api.mustache
@@ -4,13 +4,11 @@ using System.Collections.Generic;
 using System.Threading.Tasks;
 using RestSharp;
 using {{packageName}}.Client;
-using {{packageName}}.Model;
-{{#imports}}
-{{/imports}}
+{{#hasImport}}using {{packageName}}.Model;
+{{/hasImport}}
 
 namespace {{packageName}}.Api {
   {{#operations}}
-
   public interface I{{classname}} {
     {{#operation}}
     /// <summary>
diff --git a/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Api/PetApi.cs b/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Api/PetApi.cs
index 96f6f93af57..ab213f94f5a 100644
--- a/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Api/PetApi.cs
+++ b/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Api/PetApi.cs
@@ -8,7 +8,6 @@ using IO.Swagger.Model;
 
 namespace IO.Swagger.Api {
   
-
   public interface IPetApi {
     
     /// <summary>
diff --git a/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Api/StoreApi.cs b/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Api/StoreApi.cs
index 90ec2487d9d..ad9e296721c 100644
--- a/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Api/StoreApi.cs
+++ b/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Api/StoreApi.cs
@@ -8,7 +8,6 @@ using IO.Swagger.Model;
 
 namespace IO.Swagger.Api {
   
-
   public interface IStoreApi {
     
     /// <summary>
diff --git a/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Api/UserApi.cs b/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Api/UserApi.cs
index 0e3ed36c595..92b35a640e6 100644
--- a/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Api/UserApi.cs
+++ b/samples/client/petstore/csharp/SwaggerClientTest/Lib/SwaggerClient/src/main/csharp/IO/Swagger/Api/UserApi.cs
@@ -8,7 +8,6 @@ using IO.Swagger.Model;
 
 namespace IO.Swagger.Api {
   
-
   public interface IUserApi {
     
     /// <summary>