Firefighters were called to a fire at a medical health centre on Dartmouth Park Hill in Highgate.
Part of a room on the ground floor was damaged by fire.
Sadly a man was confirmed dead at the scene.
Around 100 people were evacuated from the building by staff.
The Brigade was called at 0629 and the fire was under control by 0719. Fire crews from Kentish Town and Holloway fire stations were at the scene.
The cause of the fire is under investigation by the Brigade and the Metropolitan Police Service.