Lambeth will penalise bus and taxi drivers who leave their engines running.
The new rule, designed to help cut pollution, applies to buses, coaches and taxis that leave their motors idling for more than two minutes.
It comes after a report from the campaign group Clean Air London which states that the borough exceeded its annual limit for diesel pollution for four days so far this year.
Cabinet Member for the Environment Jenny Brathwaite said: “This initiative shows we are serious about protecting our residents from the damaging effects of air pollution. However, we need the Mayor and TfL to do more given London has the highest levels of Nitrogen Dioxide pollution in Europe.
“A good start would be to expand the fleet of cleaner, greener engines to Brixton, Streatham and outer London and increase investment in cycling infrastructure to get people out of cars and onto their bikes.”