This study examines the effect of alcohol withdrawal on plasma lipids and particularly on HDL-cholesterol subfractions, in 18 middle-aged, clinically healthy but chronically drinking men, institutionalized for withdrawal therapy. Plasma lipids, total HDL and HDL3-cholesterol, Apo A-I and Apo B were assayed before and after 30-86 days of abstinence. A 38% decrease in mean total HDL-cholesterol levels was observed after withdrawal therapy (P = 0.0002), and this was due mainly to a drop in HDL3-cholesterol concentrations (-43%, P = 0.0002). The decrease in HDL2-cholesterol concentrations was also significant (-21%, P < 0.005) but less marked. These results were not dependent on quantities of alcohol ingested before therapy, on duration of hospitalization and on changes in dietary fat intake or smoking habits. Apo A-I levels decreased (-39%, P = 0.0002) and the magnitude of the decrease after alcohol withdrawal was positively related to the duration of hospitalization. Apo B levels increased (+24%, P < 0.005). Among the anthropometric parameters, arm muscle area was significantly higher after alcohol withdrawal. The energy and macronutrient intakes did not significantly change during hospitalization. It is concluded that the modifications of HDL-cholesterol, HDL3-cholesterol, HDL2-cholesterol Apo A-I and Apo B values were induced by alcohol withdrawal in this population of chronic french alcoholics.