A representative sample from the adult population of metropolitan Santiago was surveyed for prevalence and modality of alcohol consumption. The "problem drinker" was identified according to the CAGE questionnaire. Socioeconomic situation was classified according to the method of Graffar. 70% of male and 50% of female drinkers consumed less than 400 ml of ethanol per month. Prevalence of drinking in males and females was: all categories 56.2 and 19.8%, regular drinkers 40.8 and 14.4%; heavy drinkers 4 and 0.82% and problem drinkers 12.4 and 1.5%, respectively. 85% were weekend drinkers, 11% consumed alcohol throughout the week. Males consumed mostly wine and mixed alcoholic beverages, females mostly the latter. In males, drinking was related to age and not to socioeconomic condition, except for problem drinkers who were mostly found in the low category. Females problem drinkers were found mostly in the high socioeconomic group. These data may be used in planing intervention strategies to prevent damage caused by alcohol consumption.