Firefighters were called to reports of a gas leak at the junction of Poland Street and Noel Street in Soho.
A gas main at ground floor level had ruptured. Crews worked with gas engineers and the supply was isolated.
Around 400 residents and staff were evacuated from buildings in the surrounding area as a precaution.
The Brigade was called at 1304 and the incident was over for firefighters by 1450. Two fire engines from Brixton and Kensington fire stations were in attendance.