Most adults in North America are either light drinkers or abstainers, so alcohol does not cause them problems. However, a small but often highly visible minority--approximately 5% of the adult population--show major symptoms of alcohol dependence. Between these extremes, there is a sizable group of about 20% of the population, particularly young men, who are drinking at risk levels and have encountered some problems related to their alcohol use. Traditionally, physicians' efforts have focused on diagnosing and treating patients with a substantial history of alcohol dependence, and relatively little attention has been given to early intervention with nondependent problem drinkers, such as identifying patients who present in primary care settings with alcohol-related morbidity or an accidental injury. Recent evidence indicates that early intervention by primary care physicians is an effective strategy for reducing alcohol problems among patients.