Both female officers were on patrol in a marked police car at 15:30hrs on Thursday, 24 May when they were flagged down by in Hampstead Road, NW1 by a member of the public.
They alerted police to a female who was having difficulty breathing. The woman then became unconscious and stopped breathing.
The officers began administering CPR with the assistance two passing doctors and used a defribillator to help revive the woman who then started breathing of her own accord.
She was then taken by London Ambulance Service to a local hospital in a stable condition for a full check up.
Inspector Kevin Hailes from Central North said: “Both the passing doctors and paramedics said that this woman would not have survived were in not for the timely intervention and actions of the passing police officers. They remained calm under pressure to revive this woman and help her recover. Their quick thinking and dedication to serving the public is typical of so many hard working response team officers who work 24/7 shifts and respond to a wide variety of emergency calls everyday.”