Anterior cruciate ligament (ACL) rupture is a common knee injury that frequently requires surgical reconstruction and extensive postoperative rehabilitation. Preoperative rehabilitation (prehabilitation) has been suggested as a strategy to optimize physical function before surgery and enhance postoperative recovery. This prospective randomized controlled trial aims to evaluate the effectiveness of a structured six-week prehabilitation program on functional outcomes following anterior cruciate ligament reconstruction (ACLR). Seventy-six participants with complete ACL rupture scheduled for primary ACLR were randomly assigned to either a prehabilitation group or a control group receiving standard preoperative care. The prehabilitation program consisted of progressive strengthening exercises, neuromuscular training, balance exercises, and functional movement training performed three times per week. Functional outcomes were assessed at baseline, immediately before surgery, and at three and six months postoperatively using the International Knee Documentation Committee (IKDC) Score, the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Tegner Activity Scale, and the Single-Leg Hop Test. The study aims to determine whether preoperative prehabilitation predicts improved postoperative functional recovery after ACL reconstruction and to provide evidence for optimizing rehabilitation strategies in this patient population.