Twenty-one Londoners died in fires relating to smoking last year, which is more than double the year before.
The figures, released to coincide with national No Smoking Day, also show that around three fires a day are linked to smoking, with around two people a week being injured.
Fire chiefs are asking people to quit smoking to avoid the risk of dying or being hurt in a fire.
Dan Daly, the Brigade's Assistant Commissioner for Fire Safety, said: "Sadly, people often fall asleep smoking or just carelessly dispose of matches and cigarette butts which can smoulder and cause fires.
Group Manager Mark Hazelton warns of the risks of smoking.
"Overflowing ashtrays or a cigarette dropped while snoozing are typical causes of fatal fires. Quitting smoking is not only good for your health but also makes a devastating fire in your home less likely."
Those most at risk from dying in smoking-related fires are often vulnerable people including the elderly, those with mobility problems, underlying illnesses, drink or drug dependencies and live alone.
As well as asking people to quit, the Brigade is also asking carers, family members and neighbours to keep an eye out for the early warning signs that someone may be at risk of a smoking-related fire.
Assistant Commissioner Daly continued: "Family, neighbours and care workers also need to be alert to signs that someone could be at risk of a smoking related fire.
"They are often the first to see the tell-tale signs, like burn marks on carpets, furniture and clothing or smoking in bed.
"If they notice these signs or have concerns they can request a Home Fire Safety Visit from the London Fire Brigade and check our website for practical advice on how to reduce fire risk."
Smoking continues to be the largest cause of fatal fires and the third largest cause of accidental fires in the home.
Fire damage caused by a cigarette.
The Brigade's figures show in London, over the past five years, the number of fire deaths caused by smoking is 76. Last year there were 1,213 smoking-related fires, with 108 people being injured.
The majority of smoking related fires in the home started in the bedroom - while three per cent of smoking related fires start in the toilet or bathroom.
Although four times as many people smoke as they do vape, there are 255 times more smoking related fires, meaning vaping is a safer option in terms of reducing the risk of fires.
Four fires in London have been recorded in the past year due to e-smoking equipment catching fire. While there are no recorded deaths or injuries at incidents the Brigade has attended, users are reminded to never leave their e-cigarette on charge while they are away from the house or asleep, and to always use the correct type of charger for their e-cigarettes.