US Representative Gabrielle Giffords (R-TX) (C) waves to colleagues on the floor of the House of Representatives, moments after the House voted to raise the US borrowing limit, in Washington in this still image taken from video August 1, 2011. Giffords returned to the House floor on Monday for the first time since she was shot in the head in January. [Photo/Agencies]

WASHINGTON - US Rep. Gabrielle Giffords returned to the House of Representatives for the first time since she was shot last January, making a dramatic entrance Monday night during a crucial debt-limit vote and drawing loud applause and cheers from surprised colleagues.

As lawmakers stood on the floor, staring up at the vote board, Giffords slowly made her way through an entrance on the Democratic side of the chamber. Applause built and rolled like a wave through the House as lawmakers realized that their colleague had returned.

On January 8, Giffords, an Arizona Democrat, was shot in the head in the parking lot of a Tucson grocery store while meeting with constituents. Six people were killed and 13 others, including Giffords, were wounded. The man charged in the shooting, Jared Lee Loughner, has pleaded not guilty to 49 charges

On the House floor, Giffords hugged and kissed fellow lawmakers. As time ticked off on the vote, Democrats and Republicans made their way toward her.

She cast her first vote - for the debt-limit bill - and left the Capitol.

"It means so much to our country ... to witness the return of our colleague who is the personification of courage, of sincerity, of admiration throughout the country," Democratic leader Nancy Pelosi of California told the House.

Giffords has been undergoing outpatient therapy in Houston since her release from the hospital in June.

Loughner was sent to a federal prison facility in Springfield, Missouri, after a federal judge concluded he was mentally incompetent to stand trial.