Thirty-eight hips in 26 patients with alcoholism associated ischemic necrosis of the femoral head (INFH) have been evaluated by measurement of intraosseous pressure, (IOP) pressure response to a 5 ml saline load injected intraosseously and intraosseous venography. All stages of INFH were characterized by elevated IOP and/or an increased pressure response to the saline load compared to normal controls. Intraosseous venography in INFH was characterized by poor or absent visualization of the main efferent veins draining the proximal femur, diaphyseal reflux and delayed evacuation of dye from the bone. It has been possible to identify both a preradiologic and even preclinical stage of INFH. Core decompression, the removal of an 11 mm plug of bone from the head and neck of the femur, has been carried out on all hips in the study. All patients had pain prior to surgery. Eight patients in Stage I (preradiologic stage) are symptom free and without radiologic progression at follow-up, average 24 months. Only one of 5 patients in Stage II (no collapse of the femoral head) has shown X-ray progression while all remain asymptomatic. In Stage III (collapse, without acetabular involvement), core decompression offers relief of symptoms but does not appear to prevent further head collapse.