100 patients suffering from osteonecroses (including 95 with necroses of the head of the femur) were subjected to comprehensive clinical, roentgenologic and chemical laboratory examination. A triangle was established from the range of factors considered as pathogenetically important by various authors. These three outstanding factors were: disturbance of lipid metabolism, found in 41% of the patients, deviation of the liver function data, and, finally, abuse of alcohol as discovered on the basis of the case history. The statistically significant correlation of these factors makes it probable that there is actually a pathogenetic chain abuse of alcohol--hyperlipoproteinemia--arteriosclerosis--osteonecrosis. No specific importance of the uric acid and glucose metabolism could be established, since the metabolic disturbances associated with these processes are mostly linked with the observed hyperlipoproteinemia. Deliberations regarding the genesis of necrosis of the head of the femur must also take into account, over and above the relation between metabolic disturbances and stenosing vascular processes, the presence of a locally predisposing factor, such as mechanical strain or the state of enzymatic supply of the osseous tissue.