Abstract Anterior cruciate ligament (ACL) injuries affect more than 175,000 patients annually. Located in the center of the knee joint, the ACL is the major stabilizing ligament of the knee. If the ACL is injured, then the knee becomes unstable and can buckle when the person pivots. Surgeons can use autograft or allograft tissue to accomplish ACL reconstruction by using a single-bundle or double-bundle type of repair. The surgeon performs the reconstruction arthroscopically, using two ports and a small incision over the anteromedial surface of the tibia to facilitate passage of the graft and for distal fixation of the graft. Correct placement of the tibial and femoral tunnels is the most important technical aspect of the procedure. After reconstruction, the patient must undergo intense physical therapy starting one or two days after surgery. If diligent with physical therapy, then the patient can return to full activity as soon as four months after surgery.