The hypothesis that binge drinking is a benign behavior not associated with alcohol dependence, other psychiatric disorders, or problem areas, in American Indians, was tested in a sample of 582 adult Southwestern American Indian males and females in large multigenerational pedigrees. All information was obtained from semistructured psychiatric interviews that were independently blind-rated for DSM-III-R diagnoses. Three main outcome measures were used: the relationship between binge drinking and (1) alcohol dependence and other psychiatric disorders, (2) substance abuse treatment, and (3) four behavioral problem categories-violence/lawlessness, physical, social, and work. Binge drinking and alcohol dependence were strongly associated. Most binge drinkers were diagnosed as alcohol dependent. However, when controlling for alcohol dependence and other covariates, binge drinking was independently associated with an increase in odds for positive diagnoses for multiple psychiatric disorders, and for social, work, physical, and violence/lawlessness behavioral problems. In sum, binge drinking was found to be a common and severe problem with deleterious consequences in multiple domains of functioning. Assessment instruments should be designed to elicit information on binge patterns of drinking and strategies devised to provide appropriate treatment.