It happened around 3 p.m. on N.C. Highway 751 near the Calibre Park Apartments.
Police said 12-year-old Kassie Graves ran a stop sign and hit the side of the truck which was traveling north.
Graves was taken to UNC Hospitals in Chapel Hill for treatment. The driver of the truck, 59-year-old Gary Harris, was not injured.
Investigators said that speed and alcohol do not appear to have been factors in the accident. No charges are expected.
N.C. 751 was closed for more than two hours following the accident.
An account has been set up for monetary donations at the SECU Credit Union in the name of Kassie Graves.