Although a century has passed after defining the Legg-Calvé- Perthes disease, both its etiology had not been fully clarified and lack of consensus of the treatment methods lead the disease to remain still a mystery. Perthes disease can be defined as avascular necrosis of the femoral head epiphysis. Because of the high remodeling capacity of children, it is so different from its adult alike. During the course of the disease, due to presence of different factors affecting each patient, the disease progresses almost in a specific way in each patient. This situation causes difficulties in developing standard treatment protocols. The main aim of treatment is to maintain femoral head sphericity and acetabular congruency affected by the disease. To achieve these goals of treatment, commonly accepted concept is to maintain the femoral head within the acetabulum, thus to provide the shaping of the acetabulum and the femoral head. Containment principle is the key in treatment of Perthes disease. Containment principle can be achieved by either conservative or surgical methods. Although it is reported that most of the patients followed without treatment have good functional results; appropriate intervention is required considering natural course of the disease and patient specific prognostic factors. Thus, prevention of the development of degenerative coxarthrosis in adulthood can be achieved.