The vote, expected next week, comes amid a political row over the sacking of eight federal prosecutors.
The affair is being investigated by a Senate committee. The White House denies the firings were politically motivated and cites poor performance.
Analysts say the new move puts more pressure on Mr Gonzales to resign.
His position had been made more difficult by the resignation of his deputy, Paul McNulty, earlier this week.
However, Mr Gonzales would not necessarily be forced out of his job if he lost the no-confidence vote.
The attorney-general is appointed or dismissed by the president.