Myositis ossificans circumscribed is a bone and cartilage heterotopic non neoplastic proliferation inside the soft tissues. It is a benign focal heterotopic ossification process of soft tissues, and a rare disorder that occurs spontaneously or after local trauma. Clinical and radiographic appearances are quite hustler. A careful histological examination of biopsy straightens diagnosis is necessary. There is no consensus in support (surgical or/and medical). From Benign prognosis, evolution of this pathology is usually favorable. The authors report a case of giant myositis ossificans circumscribed post-traumatic localized on gluteus and adductor muscles of the right hip on a 26-year-old man. Through a review of literature the mechanism, the diagnostic methods and therapeutic will be discussed.