A 17 year-old man was referred to our clinic with a 2 years history of persistent right groin pain and inability to return to his sport activity. The onset of pain was sudden after trying to kick the ball forcefully during a competitive game of football. In his medical history, he was treated as a case of adductor strain in a private clinic. Pelvic X-rays, CT scan and MRI were taken and the patient was treated with rest, analgesia, and physiotherapy. The patient continued to have right groin pain and inability to return to his sport activity. The patient was referred to Hamad General Hospital to do bone scan in order to rule out the possibility of avascular necrosis of femoral head and the bone scan result revealed to be negative. Examination of his lower extremities and pelvis showed tenderness at the anterior aspect of hip, painful limitation of flexion and internal rotation, positive impingement sign and positive cycling test. Considering the history, clinical examination and a review of his previous imaging studies, the diagnosis of avulsion fracture of the anterior inferior iliac spine was suspected. New pelvic X-rays were done which revealed an abnormal hypertrophic malunion of the anterior inferior iliac spine fracture causing an extra-articular femoroacetabular impingement (Fig. 1). The CT scan revealed an inferiorly displaced bony fragment from the right anterior inferior iliac spine (Fig. 1). Conservative treatment in the form of nonsteroidal anti-inflammatory drugs and physiotherapy was started and continued for 12 weeks but without any response (Fig. 2), then surgical excision of the hypertrophic malunited fragment was done through the anterior hip approach. Postoperative course was uneventful and the patient was discharged from hospital after 3 days. Postoperative physiotherapy in the form of range of movement and strengthening exercises was started after 2 weeks. At 6 weeks follow up, examination of the right hip revealed full painless range of motion, negative impingement and cycling tests. The patient was followed up as an outpatient for two years postoperatively and the patient was asymptomatic with no sign of recurrence during the follow up period (Fig. 3).