You attempt to perform request which requires authorization. Just initialize account property. Look at a good article about Twitter API: http://iosdevelopertips.com/core-services/ios-5-twitter-framework-part-2.html UPD: And you can't mix POST and GET variables, I mean you have to specify all parameters to NSDictionary (POST parameters), not to URL. NSURL *updateURL = [NSURL URLWithString:@"http://