Fire fighters were called to a basement bar in Newman Passage on Sunday evening after a possible electrical fault caused a fire to start.
Eight fire engines and around 60 firefighters arrived to tackle the blaze at the Scandinavian-themed Nordic Bar in Newman Passage, off Newman Street in Fitzrovia.
The licensed premises was damaged by the fire, said the London Fire Brigade.
One man left the building before the Brigade arrived and was taken to hospital by London Ambulance Service crews after suffering smoke inhalation.
Station Commander Dean Wilkinson, who was at the scene, said: “The fire was in the basement of a five-storey building.
“Fortunately, there were no customers in the bar when the fire broke out and a member of staff managed to get out.
“Firefighters worked hard to bring the fire under control and limit the damage.”
The Brigade was called at 19:03 on Sunday 24 April and the fire was under control by 20:53. Fire crews from Soho, Euston, Lambeth, Paddington, Dowgate and surrounding fire stations were at the scene.
“The fire is believed to have been accidental and the Brigade’s Fire Investigation team believe it was caused by an electrical fault in a bottle washer,” stated the LFB.
In a statement on Twitter the Nordic Bar said: “Due to unforeseen circumstances, Nordic will be closed until further notice.”