Although musculoskeletal symptoms are common in alcoholics, little is known of the prevalence of muscle pathology in this group. Quadriceps muscle biopsies were performed in 151 alcoholics (105 men). Ninety patients showed type 2 fibre atrophy predominantly affecting the type 2b anaerobic glycolytic fibres. In contrast, 7 biopsies revealed some muscle necrosis and only 1 patient had acute rhabdomyolysis. Amongst those alcoholics with muscle atrophy the quantity of alcohol consumed in the year prior to biopsy correlated significantly with the severity of the atrophy. Atrophy was not associated with vitamin B12, folate, pyridoxine, riboflavin or thiamine deficiencies. Although patients with severe liver disease, peripheral neuropathy or malnutrition were more likely to have muscle atrophy, nerve conduction studies showed that atrophy and neuropathy each occurred independently. Sequential studies in abstaining alcoholics showed a significant improvement within 3 months and often complete recovery within a year. Continued consumption of alcohol was associated with persistence or progression of the atrophy. This study shows that reversible type 2b muscle fibre atrophy is a frequent finding in alcoholics and suggests that it is directly related to alcohol consumption and is not a consequence of malnutrition, vitamin deficiency or peripheral neuropathy.