In many studies of diverse populations it has been found that persons drinking relatively large amounts of alcohol tend to have higher blood pressures. In the Kaiser-Permanente study of about 87,000 persons, this alcohol-blood pressure association was not attributable to demographic characteristics, adiposity, reported salt use, smoking, or coffee consumption, nor could it be explained by underreporting of alcohol consumption. If the relationship is a causal one, the pathogenesis is not yet established; direct mechanisms or the effects of withdrawal from alcohol are possible explanations. The Kaiser-Permanente data suggest that about 5% of hypertension in the general population may be due to the consumption of three or more alcoholic drinks per day. Alcohol use shows a positive relation to some sequelae of hypertension but not others; the outstanding exception is coronary heart disease which is negatively related to alcohol intake, probably through different mechanisms. In most studies, cigarette smokers have shown similar or slightly lower blood pressures than non smokers. The degree to which this is due to the thinner body build of smokers, on the average, is not well established; nor is the degree to which a stronger negative relation of smoking to blood pressure might be masked by concomitant alcohol use.