The 65-year-old woman was inside her home on the 100 block of Gardiner Avenue around 10:15 a.m. on Wednesday when the theft occurred, police said.
She was waiting for a Redi-Wheels van to pick her up for a doctor's appointment, so her caregiver set the wheelchair and a walker outside on the sidewalk.
When the caregiver stepped back inside for a moment, a man allegedly grabbed the wheelchair and walker and placed them in the back of an unmarked white bobtail truck with a roll-up door.
The caregiver tried to stop the man, who was described only as a Latino male in his 30s with a slender build, but he drove away. The suspect was last seen driving on Chapman Avenue toward Airport Boulevard.
Anyone with information on this theft is asked to call South San Francisco Police at (650) 877-8900.