The HIV/Sexually Transmitted Infection (STI) risk associated with alcohol use between female commercial sex workers (FCSWs) and their customers has been understudied. We examined this relationship for 1,114 FCSWs aged 15-54 with data collected during the baseline study period (1994 to 1998) in four southern provinces of the Philippines. Two alcohol-related risk situations during commercial sex episodes were examined: prior alcohol use by an FCSW and perceived intoxication in a customer. The influence of sociodemographic variables on sexual risk behaviors was also studied. Multiple sexual risk behaviors were observed with more frequency for FCSWs if alcohol was used before commercial sex or if the episode involved a customer perceived to be intoxicated. Forty-two percent of FCSWs who had sex with an intoxicated customer were STI positive, significantly more than FCSWs who did not have sex with an intoxicated customer (28%, p < .01). Similar significant differences were found for FCSWs who did not consume alcohol before having sex and were STI positive (29%) versus FCSW who did consume alcohol before sex and were STI positive (33%, p < .01). Our analyses reinforce accumulating evidence in the field that sexual risk reduction interventions need to go beyond the behaviors of individual FCSWs to meet the layering of risks such as observed in this study. Multilevel strategies targeting customer substance use and other situational and structural factors have proven to be pivotal mediators in our other research with this population. These experiences and the limitations of this study are discussed.