About 300 guests and staff were forced to leave The Ritz hotel in central London when a fire broke out.
Four fire engines tackled the blaze
The London Fire Brigade said four engines attended the blaze in Piccadilly at 1420 GMT and were there for more than two hours.
The brigade said the fire began on ducting on a basement pipe which runs the height of the seven-storey hotel.
The basement suffered minor damage but guests and staff were later allowed back inside.