Two fire engines and 10 firefighters and officers were called to reports of a fire and explosion at a house in Demeta Close, Wembley.
A small part of the ground floor of the terraced house was damaged by the fire and there was significant structural damage caused by a gas explosion. A man and woman suffering burns were treated on the scene by London Ambulance Service crews and taken to hospital.
Around 40 people were evacuated from nearby properties as a precaution.
The Brigade was called at 2115 and the incident was over at 2355. Fire crews from Wembley fire station attended the scene.
The cause of the fire is under investigation by the Metropolitan Police Service.