Roentgenograms of 1,410 hips from 705 alcoholics were compared with those of 200 hips from 100 controls for changes consistent with non-traumatic (idiopathic) necrosis of the femoral head according to the findings diagnostic of necrosis of bone that were outlined by the Decompression Sickness Panel of the British Medical Research Council. Abnormalities were found in 45.3 per cent of the alcoholics and 49 per cent of the controls. None of the findings showed any statistical difference between the controls and the alcoholics. It was concluded that the roentgenographic findings used were not valid in detecting the early or subtle changes of necrosis of the femoral head and that the changes found in both groups are common and probably non-specific.