Clinical and laboratory observations were made on 84 patients regularly taking more than 80 g of alcohol daily. Macrocytosis was present in 84.5%, but only 13% were anaemic. Twenty-seven of the 57 bone marrows sampled were abnormal, 20 showing megaloblastic changes, mostly mild in degree. Serum, red cell, and liver folate levels were reduced in 28%, 35% and 31% of patients respectively. Liver folate concentration showed good correlation with serum and red cell folates. The folate deficiency was more severe in those patients, more often female, who had inadequate diets or drank wine and spirits rather than beer. The amount of alcohol consumption and extent of liver damage did not affect folate status. The findings suggest that folate deficiency is common among alcoholics in this country. More frequently, however, patients had macrocytosis, sometimes with megaloblastosis, in the absence of folate deficiency emphasizing the direct toxic effect of alcohol on the developing erythroblast.