Avulsion of the hamstring tendon from the ischial tuberosity is common in many sports, especially with younger athletes. The injury results from a sudden forceful flexion of the hip joint when the knee is extended and the hamstring muscles powerfully contracted. Early diagnosis and surgical repair with reattachment of avulsed muscles to the ischial tuberosity restore function and correct deformity. But, a delay in the diagnosis and treatment leads to a poor result functionally and clinically. Complication, such as heterotopic ossification and failure of the fixation, etc., were reported following a surgical procedure for this injury. However, sciatic nerve injury has not been reported in the literature. We report our experience of a sciatic nerve palsy after surgery that was performed three months after that the initial injury.