OBJECTIVE: Alcoholism is a problem of worldwide concern. Full appreciation of this international problem requires that adequate diagnostic measures be constructed and that comparable measures for different cultures be available so that valid differences in prevalence across cultures can be detected. A Spanish-language version of the Diagnostic Interview Schedule (DIS) has been used for epidemiologic studies of alcohol abuse and dependence in Los Angeles Mexican- Americans and mainland Puerto Ricans, and the authors used the same instrument to conduct a similar study in Peru. METHOD: A population sample (N = 815) from the Independencia district of Lima, Peru, was chosen for interviews with a revised form of the Spanish translation of the DIS. Lifetime prevalence rates of alcoholism and other DSM-III diagnoses were determined. RESULTS: The prevalence of alcohol abuse or dependence was higher among the men (34.80%) than among the women (2.46%), but the onset for women was earlier. Alcoholism was strongly associated with antisocial personality disorder and with drug abuse or dependence. CONCLUSIONS: The prevalence of alcoholism for the Peruvian men is higher than prevalences for men in U.S. studies, but the prevalence among the Peruvian women is one of the lowest reported. The high prevalence among men is likely due to cultural mores but may also be linked to the stresses found in impoverished societies undergoing rapid social, cultural, and economic change.