A method and apparatus for fast control channel feedback for multiple downlink carrier operations are disclosed. A wireless transmit/receive unit (WTRU) receives signals over a plurality of downlink carriers, generates feedback for each of the plurality of downlink carriers based on the received signals, and transmits via a plurality of antennas, the feedback for at least one of the plurality of downlink carriers over a first physical channel and feedback for another of the plurality of downlink carriers over a second physical channel.