Four fire engines and around 25 firefighters tackled a fire at a restaurant and office building on New Road in Whitechapel.
The ducting from ground floor to roof level was destroyed by the fire. There were no reports of any injuries.
The fire is believed to have been accidental and caused by a build up of grease within the ducting.
A London Fire Brigade spokesperson said: "We'd like to remind restaurant and takeaway owners to ensure they don't have dirty ducting. If you don't clean the ducting in your extraction system regularly, you're at a greater risk of ducting fires.
"You should also make sure you keep the hob, cooker hood and extractor fan clean too – built up fat and grease can ignite and cause a fire."
One of the Brigade's 32-metre turntable ladders was used at the scene to help fight the fire from above.
The Brigade was called at 1352 and the incident was over for firefighters at 1546. Crews from Whitechapel, Shadwell, Bethnal Green and Shoreditch fire stations attended the scene.