diff --git a/AFNetworking/AFHTTPRequestOperation.h b/AFNetworking/AFHTTPRequestOperation.h
index 350b64a..235cc1a 100644
--- a/AFNetworking/AFHTTPRequestOperation.h
+++ b/AFNetworking/AFHTTPRequestOperation.h
@@ -31,6 +31,8 @@
     NSIndexSet *_acceptableStatusCodes;
     NSSet *_acceptableContentTypes;
     NSError *_HTTPError;
+    dispatch_queue_t _successCallbackQueue;
+    dispatch_queue_t _failureCallbackQueue;
 }
 
 ///----------------------------------------------
@@ -71,6 +73,17 @@
  */
 @property (readonly) BOOL hasAcceptableContentType;
 
+/** 
+ The callback dispatch queue on success. If this is NULL (default), the main queue is used.
+ */
+@property (nonatomic) dispatch_queue_t successCallbackQueue;
+
+/** 
+ The callback dispatch queue on failure. If this is NULL (default), the main queue is used.
+ */
+@property (nonatomic) dispatch_queue_t failureCallbackQueue;
+
+
 /**
  A Boolean value determining whether or not the class can process the specified request. For example, `AFJSONRequestOperation` may check to make sure the content type was `application/json` or the URL path extension was `.json`.
  
diff --git a/AFNetworking/AFHTTPRequestOperation.m b/AFNetworking/AFHTTPRequestOperation.m
index 38802c1..2fa2326 100644
--- a/AFNetworking/AFHTTPRequestOperation.m
+++ b/AFNetworking/AFHTTPRequestOperation.m
@@ -30,6 +30,9 @@
 @synthesize acceptableStatusCodes = _acceptableStatusCodes;
 @synthesize acceptableContentTypes = _acceptableContentTypes;
 @synthesize HTTPError = _HTTPError;
+@synthesize successCallbackQueue = _successCallbackQueue;
+@synthesize failureCallbackQueue = _failureCallbackQueue;
+
 
 - (id)initWithRequest:(NSURLRequest *)request {
     self = [super initWithRequest:request];
@@ -46,6 +49,8 @@
     [_acceptableStatusCodes release];
     [_acceptableContentTypes release];
     [_HTTPError release];
+    if (_successCallbackQueue) { dispatch_release(_successCallbackQueue), _successCallbackQueue=NULL;}
+    if (_failureCallbackQueue) { dispatch_release(_failureCallbackQueue), _failureCallbackQueue=NULL;}
     [super dealloc];
 }
 
@@ -85,6 +90,34 @@
     return !self.acceptableContentTypes || [self.acceptableContentTypes containsObject:[self.response MIMEType]];
 }
 
+- (void)setSuccessCallbackQueue:(dispatch_queue_t)successCallbackQueue {
+    if (successCallbackQueue != _successCallbackQueue) {
+        
+        if (_successCallbackQueue) {
+            dispatch_release(_successCallbackQueue);
+        }
+     
+        if (successCallbackQueue) {
+            dispatch_retain(successCallbackQueue);
+            _successCallbackQueue = successCallbackQueue;
+        }
+    }    
+}
+
+- (void)setFailureCallbackQueue:(dispatch_queue_t)failureCallbackQueue {
+    if (failureCallbackQueue != _failureCallbackQueue) {
+        
+        if (_failureCallbackQueue) {
+            dispatch_release(_failureCallbackQueue);
+        }
+        
+        if (failureCallbackQueue) {
+            dispatch_retain(failureCallbackQueue);
+            _failureCallbackQueue = failureCallbackQueue;
+        }
+    }    
+}
+
 - (void)setCompletionBlockWithSuccess:(void (^)(AFHTTPRequestOperation *operation, id responseObject))success
                               failure:(void (^)(AFHTTPRequestOperation *operation, NSError *error))failure
 {
@@ -95,13 +128,13 @@
         
         if (self.error) {
             if (failure) {
-                dispatch_async(dispatch_get_main_queue(), ^(void) {
+                dispatch_async(self.failureCallbackQueue ? self.failureCallbackQueue : dispatch_get_main_queue(), ^{
                     failure(self, self.error);
                 });
             }
         } else {
             if (success) {
-                dispatch_async(dispatch_get_main_queue(), ^{
+                dispatch_async(self.successCallbackQueue ? self.successCallbackQueue : dispatch_get_main_queue(), ^{
                     success(self, self.responseData);
                 });
             }
diff --git a/AFNetworking/AFImageRequestOperation.m b/AFNetworking/AFImageRequestOperation.m
index e004e9d..d1f4d2b 100644
--- a/AFNetworking/AFImageRequestOperation.m
+++ b/AFNetworking/AFImageRequestOperation.m
@@ -231,13 +231,13 @@ static dispatch_queue_t image_request_operation_processing_queue() {
         dispatch_async(image_request_operation_processing_queue(), ^(void) {
             if (self.error) {
                 if (failure) {
-                    dispatch_async(dispatch_get_main_queue(), ^(void) {
+                    dispatch_async(self.failureCallbackQueue ? self.failureCallbackQueue : dispatch_get_main_queue(), ^{
                         failure(self, self.error);
                     });
                 }
             } else {                
                 if (success) {
-                    dispatch_async(dispatch_get_main_queue(), ^(void) {
+                    dispatch_async(self.successCallbackQueue ? self.successCallbackQueue : dispatch_get_main_queue(), ^{
                         success(self, self.responseImage);
                     });
                 }
diff --git a/AFNetworking/AFJSONRequestOperation.m b/AFNetworking/AFJSONRequestOperation.m
index 5c651de..cc7d661 100644
--- a/AFNetworking/AFJSONRequestOperation.m
+++ b/AFNetworking/AFJSONRequestOperation.m
@@ -125,7 +125,7 @@ static dispatch_queue_t json_request_operation_processing_queue() {
         
         if (self.error) {
             if (failure) {
-                dispatch_async(dispatch_get_main_queue(), ^(void) {
+                dispatch_async(self.failureCallbackQueue ? self.failureCallbackQueue : dispatch_get_main_queue(), ^{
                     failure(self, self.error);
                 });
             }
@@ -133,17 +133,19 @@ static dispatch_queue_t json_request_operation_processing_queue() {
             dispatch_async(json_request_operation_processing_queue(), ^(void) {
                 id JSON = self.responseJSON;
                 
-                dispatch_async(dispatch_get_main_queue(), ^(void) {
-                    if (self.JSONError) {
-                        if (failure) {
+                if (self.JSONError) {
+                    if (failure) {
+                        dispatch_async(self.failureCallbackQueue ? self.failureCallbackQueue : dispatch_get_main_queue(), ^{
                             failure(self, self.JSONError);
-                        }
-                    } else {
-                        if (success) {
-                            success(self, JSON);
-                        }
+                        }); 
                     }
-                }); 
+                } else {
+                    if (success) {
+                        dispatch_async(self.successCallbackQueue ? self.successCallbackQueue : dispatch_get_main_queue(), ^{
+                            success(self, JSON);
+                        });
+                    }
+                }
             });
         }
     };    
diff --git a/AFNetworking/AFPropertyListRequestOperation.m b/AFNetworking/AFPropertyListRequestOperation.m
index bb7a41b..0fcade0 100644
--- a/AFNetworking/AFPropertyListRequestOperation.m
+++ b/AFNetworking/AFPropertyListRequestOperation.m
@@ -125,7 +125,7 @@ static dispatch_queue_t property_list_request_operation_processing_queue() {
         
         if (self.error) {
             if (failure) {
-                dispatch_async(dispatch_get_main_queue(), ^(void) {
+                dispatch_async(self.failureCallbackQueue ? self.failureCallbackQueue : dispatch_get_main_queue(), ^{
                     failure(self, self.error);
                 });
             }
@@ -133,7 +133,7 @@ static dispatch_queue_t property_list_request_operation_processing_queue() {
             dispatch_async(property_list_request_operation_processing_queue(), ^(void) {
                 id propertyList = self.responsePropertyList;
 
-                dispatch_async(dispatch_get_main_queue(), ^(void) {
+                dispatch_async(self.successCallbackQueue ? self.successCallbackQueue : dispatch_get_main_queue(), ^{
                     if (self.propertyListError) {
                         if (failure) {
                             failure(self, self.propertyListError);
diff --git a/AFNetworking/AFXMLRequestOperation.m b/AFNetworking/AFXMLRequestOperation.m
index b6b3a2b..ee7865a 100644
--- a/AFNetworking/AFXMLRequestOperation.m
+++ b/AFNetworking/AFXMLRequestOperation.m
@@ -188,13 +188,15 @@ static dispatch_queue_t xml_request_operation_processing_queue() {
         
         if (self.error) {
             if (failure) {
-                dispatch_async(dispatch_get_main_queue(), ^(void) {
+                dispatch_async(self.failureCallbackQueue ? self.failureCallbackQueue : dispatch_get_main_queue(), ^{
                     failure(self, self.error);
                 });
             }
         } else {
             if (success) {
-                success(self, self.responseXMLParser);
+                dispatch_async(self.successCallbackQueue ? self.successCallbackQueue : dispatch_get_main_queue(), ^{
+                    success(self, self.responseXMLParser);
+                });
             }
         }
     };