Pest control officers were called to the TV chef's Maze Grill eaterie after diners spotted a rodent scurrying under a table, hotly pursued by worried staff.
Diner David Moreton says, "It was extraordinary to think a mouse was loose in one of London's best restaurants. My wife can't stand them and was absolutely terrified. It totally ruined her night."
A spokesperson for Gordon Ramsay Holdings Ltd explains, "We have apologised. Pest controllers have since given us a clean bill of health."
It's the latest setback for the Hell's Kitchen star - last week (ends24Oct10) his father-in-law Chris Hutcheson stepped down as CEO of Ramsay's business empire.
The chef was also dealt another blow in August (10) when he received three outstanding U.S. tax bills, with one totalling $484,500 (£323,000).