The accident occurred at C Street and the Boulevard at around 4:30 p.m.
Police say the 20-year old was struck and thrown an estimated 30 feet.
He was transported by Philadelphia fire medics to Albert Einstein Medical Center for treatment.
He listed in critical, but stable condition.
Police say the SUV that struck the victim was actually sideswiped by a white mid sized box truck. The truck forced the SUV off the road, striking the pedestrian.
The truck was last seen heading north on Roosevelt Boulevard.
Police are investigating.