This study examines alcohol use, transactional sex (TS), and sexually transmitted infection (STI) risk among sugar plantation residents near Moshi, Tanzania, from 2002 to 2004. We compare popular discourse gathered through ethnographic methods with cross-sectional questionnaire and STI prevalence data to illuminate the close correspondence of alcohol use and TS with STI transmission. People attributed to alcohol varied consequences: some socially desirable (relaxing, reducing worries) and others (drunkenness, removing shame) thought to put alcohol abusers at risk for STIs. TS-exchanging money, food, gifts, alcohol or work for sex-was not stigmatized, but people believed that seeking sexual partners for money (or providing money to sexual partners) led to riskier sexual relationships. We explore popular discourse about how alcohol use and TS independently and in combination led to increased STI exposure. Popular discourse blamed structural circumstances-limited economic opportunities, few social activities, separated families-for risky sex and STIs. To understand individual behavior and risk, we surveyed 556 people. We measured associations between their self-reported behaviors and infection with herpes simplex virus type-2 (HSV-2), syphilis, and HIV in 462 participants who were tested. Alcohol abuse was associated with prevalent STI and HIV infection. Exchanging sex for alcohol and work were both associated with prevalent STI. Participants who both abused alcohol and participated in TS had greatest risk for STI. Findings from the two analytic methods-interrogation of popular discourse, and association between self-reported behavior and STIs-were largely in agreement. We posit explanations for discrepancies we found through the concepts of sensationalization, self-exceptionalization, and the influence of an authoritative moral discourse.