Avascular necrosis of the hip is a pathological entity comprising inadequate blood supply to the femoral head. The following risk factors increase the risk of osteonecrosis, e.g., alcohol intake, steroids, diabetes, and sickle cell disease. Use of hyperbaric oxygen therapy improves patient’s quality of life and leads to a better clinical and radiological result in initial stages of the disease. It delays and helps prevent femoral head collapse.