Eight fire engines and around 60 firefighters dealt with flooding in the area around Enford Street in Marylebone.
A burst 9cm water main flooded an area of around 200m by 100m, leaving up to 2m of water in basement flats along Enford Street and York Street. Approximately 14 residents from ground floor and basement properties were evacuated as a precaution. There were no reports of any injuries.
Firefighters used flood barriers and sandbags to divert flood water away from homes.
Station Commander Brien O'Keeffe, who was at the scene, said: "Crews worked hard to assist partner agencies to resolve the incident as quickly as possible in a safe manner and are continuing to support local businesses and the community.
"Members of the public are advised to continue to avoid the local area. Traffic restrictions are in place on Marylebone Road, Seymour Place, Crawford Street and Gloucester Place."
The Brigade's Control Officers took the first of 15 calls to the incident at 0520 and sent crews from Paddington, Euston, Soho, Chelsea, Kentish Town and surrounding fire stations to the scene. The incident was over for firefighters by 1138.