The 5K run and walk started at 9 a.m. outside the Ferry Building, where participants ran along the Embarcadero.
So far this year, the organization has raised nearly $140,000 for breast cancer research and treatments, so they're almost at their $200,000 goal.
ABC7 News' Natasha Zouves emceed the event in San Francisco.
The Susan G. Komen Race for The Cure is the largest and most successful education and fundraising event for breast cancer.