Four fire engines and around 25 firefighters attended a fire at a dry cleaners on Lewisham Way in Lewisham.
Part of the ground floor was damaged by fire. There were no reports of any injuries.
The Brigade was called at 2347 and Control Officers mobilised crews from New Cross, Lewisham, Deptford and Lee Green fire stations to the scene. The fire was extinguished by 0046.
The fire is believed to have been caused by self-heating textiles.
A London Fire Brigade spokesperson said: "These types of fires often involve textiles that become contaminated with oil, most commonly linseed, massage and cooking oil on tea towels, tablecloths and chef whites. Make sure you check the manufacturer's cleaning recommendations of your textiles before washing.
"Sometimes when materials are cleaned and put in tumble dryers, the heat from the tumble drying cannot escape. This can result in a high enough temperature allowing it to build up to a point where it smoulders and eventually ignites.
"If you are washing and then drying on a hot cycle, always use the cooling cycle on the tumble dryer so it cools down and allow the heat to dissipate properly, before stacking laundered items together.”