It happened around 11:30 p.m. Thursday at 12th and Chestnut in Center City.
The officer was in the process of transporting someone to the hospital when the crash happened.
The driver of the other car was tested for DUI but, while police say he was drinking, he was below the legal limit.
The officer suffered bumps and bruises.
The person being driven the hospital did not suffer additional injuries, but it is not yet known why that person was being transported.