The 80-year-old pensioner only realised her mix-up after one of her daughters dropped by later in the day and noticed the car bore no resemblance to her mother's.
She had left her own car in a supermarket car park, and proceeded to drive the other vehicle to her garage at her home in southern Sweden.
The Local reports that the stolen vehicle had its keys left in the ignition.
Although the vehicle she had driven was reported stolen, the woman will not be subject to a police investigation.
Both cars are now possessed by their rightful owners.