The osteoclast activity (number of osteoclasts per surface bone section) and the osteoid abundance (percentage of trabecular bone surface covered with osteoid) were measured in iliac crest biopsies from 38 men with alcoholism. These patients had histories of decades of over-consumption of alcohol and repeated injuries, as well as medical complications. In older individuals, the bone mineral content of the forearms decreased so that the reduction in relation to age was comparable to that of women rather than men. Osteoid seams increased in thickness only in alcoholics who had previously undergone gastric resection. Otherwise, there were no differences in osteoid seams in alcoholics and control nonalcoholism patients. Osteoclasts, however, were more abundant in the iliac crest biopsies from alcoholics than from the nonalcoholic group. Osteoclasts were also more numerous in alcoholics who had undergone gastric resection although, in the other cases, there were also significant increases above normal. In any case, the nutritional effects of alcoholism on the skeleton were relatively slight inasmuch as there was no case of advanced osteomalacia. Nevertheless, alcoholism causes bone changes, both systemic (possibly hormonal) and local in nature, and is characterized by bone resorption.