I've used NSURLConnection many times, and never got a problem. But i have a problem when i try to cancel it. Basically, i create a NSURLConnection on the main thread with method : Code: connection = [[NSURLConnection alloc] initWithRequest:request delegate:self]; When an event happen (click on a button), i call Code: [connection cancel]; [connection release]; connection = nil; However, it still call the delegate method. From what i understand, it should not be like that. Anyone know about this ?