The relationship between alcohol consumption and coronary heart disease (CHD) in various epidemiologic study designs is consistent, showing protection at < or = 2 drinks per day, with an increase in risk of CHD in several studies at higher alcohol consumption levels. Studies of potential mediators of the effects of alcohol on CHD show beneficial effects on HDL cholesterol and some coagulation factors, but, at higher levels of consumption, adverse effects on blood pressure, arrhythmias, and the myocardium. Statistical modeling of pathways for alcohol's effect on coronary disease is consistent with a protective pathway via elevated HDL cholesterol and an adverse pathway through elevated blood pressure. Maximum benefit for CHD appears to be reached at only one drink daily. Given that alcohol is an intoxicating and potentially addictive substance with a high abuse potential, and given the high morbidity and mortality associated with heavier drinking, public health recommendations to consume alcohol are contraindicated.