According to investigators, the crime happened shortly before 2 a.m. at the Amera gas station at 4708 West Girard Avenue.
The victim pulled into the station driving a white Toyota RAV4. Police said as he was pumping gas, the offender approached him, pulled out a gun and demanded his keys.
The victim complied and the suspect was last seen heading east on Girard Avenue.
The victim was not injured during the incident.
Anyone with any information is asked to call police.