Giguère K, et al. - Researchers here investigated risk compensation among female sex workers (FSW) on HIV preexposure prophylaxis (PrEP), and examined whether self-report of sexual behaviors is subject to bias. They conducted a prospective observational PrEP demonstration study among FSW in Cotonou, Benin, with 255 participants. Of these, 120 (47.1%) completed their follow-up. They noted a decrease in the prevalence of sexually transmitted infections (STIs) from 15.8% (95% confidence interval: 11.8% to 21.0%) at baseline to 2.1% at 24 months of follow-up (95% confidence interval: 0.4% to 10.2%). However, neither self-report of unprotected sex in the last 2 or 14 days, nor prostate-specific antigen or Y chromosomal DNA exhibited any trend over the same period. Findings yielded no evidence of risk compensation, and a decrease in STI among FSW on PrEP. PrEP intervention seems to represent an opportunity to control STI among FSW.