It happened around 7:30 p.m. in the 3800 block of Spruce Street.
The victim, identified as 22-year-old Monae Mosey, was riding her bike on her way to CHOP to visit her sick child.
Surveillance video shows that Mosey had fallen off her bike and was attempting to get up when she was hit by a car travelling westbound.
The driver of the vehicle kept going.
Fortunately another passerby rushed to help Mosey and she was taken to the Hospital of the University of Pennsylvania in critical condition.
The car is described as a dark four-door sedan with a light-colored out-of-state or vanity plate on the front.
The vehicle may have possible damage to the left front fender or bumper.
Anyone with information is urged to contact Philadelphia Police at 215-686-TIPS (8477), text a tip to PPD TIP (773847) or through PhillyPolice.com.