Five fire engines and around 35 firefighters were called to the blaze at a block of flats under construction on Prestons Road in Canary Wharf.
Part of a five-roomed flat on the 35th floor was damaged by the fire. One man suffering smoke inhalation left the building before the Brigade arrived.
He was treated on scene by London Ambulance Service crews. A further 400 staff were evacuated from the site as a precaution.
The area is home to the Wood Wharf development being built by Canary Wharf Contractors.
The firm said: “The London Fire Brigade were on site yesterday responding to a small fire within the Wood Wharf construction site.
“One person was treated by the London Ambulance Service for smoke inhalation. We are supporting LFB’s investigation.”