It's an effort to reduce violence in the neighborhood.
Similar gun buyback events have taken place around the Bay Area.
Supervisor David Campos, who represents the Mission District, is donating $75,000 from his discretionary fund to pay for Thursday's buyback.
It's happening in the parking lot of the U.S. Bank at 22nd and Capp streets from 6 to 8 p.m.
Those with working guns will receive $100, no questions asked. $200 will exchanged for assault rifles.