The American Medical Response ambulance was on its way to an incident when it landed on its side at the intersection of 16th Street and South Van Ness Avenue around 12:15 p.m., San Francisco fire spokeswoman Mindy Talmadge said.
Talmadge said the emergency vehicle was involved in an accident with an unknown number of other vehicles.
No major injuries have been reported, she said.
Police, as of 12:45 p.m., were monitoring traffic in the area as crews worked to remove the flipped ambulance.