Doctors Against Diesel claim 9,400 Londoners a year die prematurely from breathing in toxic fumes from diesel engines.
Paris, Madrid, Mexico City and Athens have committed to a ban on diesel vehicles by 2025.
Opponents to the campaign have called the proposals "impractical" and warned a blanket ban could "backfire".
Doctors Against Diesel - comprising doctors, nurses and health professionals - are calling for Sadiq Khan, Mayor of London, to commit to phasing out diesel vehicles from London.
Mr Khan has already said he wants to get rid of diesel buses by 2018.
A spokesman for the mayor said he has no legal powers to ban cars in London, and is calling on the government "to face its responsibility and implement a national diesel scrappage scheme now".
"The mayor has more than doubled air quality funding and is doing everything in his power to tackle London's toxic air and rid the city of the most polluting vehicles, but he cannot do this alone" the spokesman added.