St John Ambulance will visit Barnet as part of its 'Save a Life in September' campaign.
Volunteers from the charity will show how to perform CPR, treat a heart attack victim or someone who is choking or bleeding, and how to place a victim in the recovery position.
Research by St John Ambulance revealed that every year 140,000 people die in situations in which they could be saved by first aid.
Len Bamber, regional director of London St John Ambulance, said: "Learning first aid is one of the single most important things you can do in your life.
"You never know when you may need it – at work, at home, in school, playing sport – you just don’t know.”
The lessons will be at The Spires and Brent Cross shopping centres on Saturday 28 September between 10am to 4pm.