Moderate alcohol consumption has been reported to provide protection against coronary heart disease. We studied serum lipid values in 380 men, including 184 controls (37 teetotalers and 147 moderate drinkers), 90 heavy drinkers, and 106 alcoholics. Total cholesterol values were significantly lower among alcoholics than controls (mean +/- SEM, 5.43 +/- 0.15 mmol/L [210 +/- 5.8 mg/dL] vs 6.01 +/- 0.08 mmol/L [232 +/- 3.1 mg/dL]), but their high-density lipoprotein (HDL) cholesterol values were higher (1.66 +/- 0.07 mmol/L [64 +/- 2.7 mg/dL] vs 1.14 +/- 0.02 mmol/L [44 +/- 0.8 mg/dL]). Accordingly, there was a highly significant difference in the HDL/total cholesterol ratio (0.32 +/- 0.13 vs 0.19 +/- 0.01). Heavy drinkers had significantly higher total cholesterol values than controls (6.30 +/- 0.13 mmol/L [244 +/- 5.0 mg/dL] vs 6.01 +/- 0.08 mmol/L [232 +/- 3.1 mg/dL]); the same was true of HDL cholesterol values (1.25 +/- 0.07 mmol/L [48 +/- 2.7 mg/dL] vs 1.14 +/- 0.02 mmol/L [44 +/- 0.8 mg/dL]). No significant difference was found in the HDL/total cholesterol ratio between controls and heavy drinkers or between teetotalers and moderate drinkers. Therefore, moderate alcohol intake apparently does not change HDL/total cholesterol ratio; if moderate drinking is protective against coronary heart disease, the mechanism is probably not via lipids.