This paper reports results of an analysis of the association between alcohol intoxication and injection and sexual HIV risk behaviors among 557 Hispanic heroin and cocaine injectors, not in treatment, who were recruited in poor communities in Puerto Rico. Subjects were part of a longitudinal prevention-intervention study aimed at reducing drug use and HIV risk behaviors. Participants reported a high prevalence of co-occurring conditions, particularly symptoms of severe depression (52%) and severe anxiety (37%), measured by Beck's Depression Index and Beck's Anxiety Index, respectively. Alcohol intoxication during the last 30 days was reported by 18% of participants. Associations were found between alcohol intoxication and both injection and sexual risk behaviors. In the bivariate analysis, subjects reporting alcohol intoxication were more likely to inject three or more times per day, pool money to buy drugs, share needles, and share cotton. They were also significantly more likely to have a casual or paying sex partner and to have unprotected sex with these partners. After adjustment, sharing needles and cotton, having sex with a paying partner or casual partner, and exchanging sex for money or drugs were significantly related to alcohol intoxication. HIV prevention programs, to be effective, must address alcohol intoxication and its relation to injection and sexual risk behaviors as a central issue in HIV prevention among drug injectors. (C) 2004 Elsevier Ireland Ltd. All rights reserved.