Fresno Police say it happened in the area of Harrison and Cornell avenues just after 11 am Wednesday.
Officers say a woman was putting groceries away while her kids were still in the car. They say she then heard and saw her car driving away.
The woman ran after the car while screaming for help.
Police say others heard the woman and got into their cars to chase the suspect down.
They were able to block the stolen car on Harrison north of Shields and hold the man down until officers arrived.
He was taken into custody.
Both children are safe and back with their mother.
Police say the man was on probation and faces multiple charges.