Osteonecrosis of the femoral head is a progressive condition that often leads to collapse of the femoral head. The ultimate goal in the treatment for osteonecrosis of the hip is preservation of the femoral head. However, the condition is difficult to treat because it is associated with a number of different diseases, and the etiology and natural history of the condition have not been definitively determined. The delineation of new information regarding the etiology, pathogenesis, and natural history of osteonecrosis is ongoing. Core decompression, vascularized and nonvascularized bone grafting procedures, and arthroplasty procedures play an important role in treatment.