Four fire engines and 21 firefighters and officers were called to a reports of smoke issuing at a restaurant at the Trocadero in Piccadilly Circus.
Crews dealt with a small fire in the internal ventilation system at the basement level of an eight storey building. Seven people left the building before the arrival of the Brigade and there were no reports of any injuries.
The Brigade was called at 0020 and the fire was under control at 0220. Fire crews from Soho and Lambeth fire stations attended the scene.
The cause of the fire is under investigation.