Legg-Calve-Perthes disease (LCPD) is a painful hip disorder of childhood characterized by avascular necrosis of the femoral head. Patients are usually 4-12 years of age. Athough the precise cause of LCPD is not yet known, but the studies and hypotheses point to some co-factors such as environment, trauma, synovitis, coagulopathy, vascular abnormalities and genetics. It was noticed that males are more susceptible than females at a rate of 4 to 5 times. Symptoms and signs are including pain, limp and limited ROM of the affected hip which vary from one patient to another. Early diagnosis and treatment of LCPD is important for normal development of the hip. Despite early screening and treatment of LCPD, it is not uncommon to see an older child with neglected LCPD. Cases with neglected LCPD need aggressive surgical treatment to restore normal hip joint and prevent irreversible femoral head damage, osteoarthritis and obviate the need for arthroplasty in young adulthood. In the first part of this thesis, a review of the literature was done to discuss the following items: blood supply of the femoral head, biomechanics, etiology, pathology, diagnosis and management of LCPD.