The relationship between patterns of alcohol consumption and adverse consequences of drinking was examined in a cross-sectional study of hospital patients. Regular drinking that exceeds 40 g per day by males and 25 g per day by females was found to increase significantly the risk of a variety of alcohol-related medical and psychosocial problems. Similarly, frequent consumption of six or more drinks per occasion significantly increased the risk of problems for both men and women. Among males elevated average daily consumption contributed more to alcohol-related problems than frequency of intoxication, while the opposite was true for females. These results indicate that the frequency and amount of alcohol consumption are important risk factors for both nonalcoholics and alcoholics, and that measures of drinking pattern may be useful for screening purposes.