Partygoers and clubbers who inhale laughing gas could be fined up to £1,000 under special powers adopted by a local council.
Lambeth is the first London borough to launch a crackdown on 'legal highs'. It is believed to be the first council in Britain to target laughing gas.
The move follows the death of a teenager in south London at the weekend.
Ally Calvert, 18, collapsed and died from heart failure in Bexley. Reports said he inhaled laughing gas at a party.
Lambeth plans to introduce a Public Spaces Protection Order to ban laughing gas and other legal highs.
Users will be given on the spot fines of £100 or face a penalty of up to £1,000 if the case is referred to magistrates.
The council said it was acting after complaints from residents about litter and anti social behaviour around clubs in Vauxhall, Brixton, Streatham and Clapham.
In the last year, Lambeth police dealt with 57 cases including robbery, theft, anti social behaviour and sexual assault where legal highs were a factor.
Legal highs are simply not safe – we saw that just days ago with the death of a teenager who had inhaled laughing gas. It is our duty to keep our residents safe and this new order should deter people from supplying and using legal highs in the borough.
The ban will come into force on August 17th.
A neighbouring, Kensington and Chelsea, plans to use similar PSPO powers to ban the owners of powerful sports cars from revving their engines and racing.