Eight fire engines and around 60 firefighters were called to a fire affecting a range of derelict warehouses on Fraser Road in Bexley.
Part of a single-storey unit was damaged by fire. There were no injuries reported.
The Brigade's Control Office took the first call at 0240 and fire crews from Erith, Bexley, Plumstead and other surrounding fire stations attended the scene. The fire was brought under control by 0440.
The cause of the fire has been recorded as undetermined.