Four fire engines and around 25 firefighters were called to a flat fire on Darling Row in Bethnal Green.
Part of a five-roomed flat on the fourth floor of the building was damaged by fire. There were no reports of any injuries.
A London Fire Brigade spokesperson said: “Smoke alarms fitted inside the property alerted residents to the fire who promptly left the flat and called 999.
"This is a reminder of the importance of having working smoke alarms in your home. They give the earliest possible warning to fire, providing time to escape.
"You should have smoke alarms in every room where a fire could start, plus a heat alarm in the kitchen.”
The Brigade was called at 1939 and the fire was under control by 1957. Fire crews from Bethnal Green, Whitechapel, Poplar and Shoreditch fire stations attended the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.