The shooting was reported at 9:07 a.m. in the area of McKinnon Avenue and Lane Street, San Francisco police spokeswoman Officer Tracy Turner said.
The victim suffered gunshot wounds to his lower torso and was taken to San Francisco General Hospital, Turner said. She did not know the man's condition as of about 10 a.m.
No arrests have been made in the case, she said.
Anyone with information about the shooting is asked to call the Police Department's anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411 with "SFPD" in the message.