The House of Representatives passed a resolution, sponsored by Rep. Debbie Wasserman Schultz, D-Fla., a close friend of Giffords, by a 419-0 vote to rename a room in the Capitol Visitor Center the Gabriel Zimmerman Meeting Room, the Los Angeles Times reported.
Zimmerman, who was 30, was one of six people killed in the Jan. 8 attempt on Giffords' life in Tucson that also wounded the Arizona Democrat and 12 others.
Zimmerman, one of the first staffers hired by Giffords after her 2006 election, most recently had been director of community outreach and helped plan the "Congress On Your Corner" where the shootings took place.
The resolution stated Zimmerman "was the first congressional staffer in history to be murdered in the performance of his official duties."
"And God willing, the last," House Speaker John A. Boehner, R-Ohio, said in remarks on the House floor Wednesday.
"Let us honor Gabe's memory by following his example of service to this institution, which remains the direct voice of the American people and their will," Boehner said.