Current HIV prevention counseling strategies rely largely on interventions aimed at changing behaviors. Among these is HIV prevention counseling and testing, which has been a prominent component in the federally supported strategies for HIV/AIDS prevention in the U.S.. To assess the efficacy of HIV counseling in reducing risk behaviors and preventing HIV infection and other sexually transmitted diseases, a multicenter, randomized controlled trial is being conducted among sexually transmitted disease clinic patients (Project RESPECT). The trial compares three separate HIV prevention strategies on increasing condom use and decreasing new cases of sexually transmitted diseases. The strategies are (a) Enhanced HIV Prevention Counseling, a 4-session individual counseling intervention based on behavioral and social science theory; (b) HIV Prevention Counseling, a 2-session individual pre- and post test counseling strategy that attempts to increase perception of risk and reduce risk behaviors using small, achievable steps; and (c) HIV Education, a brief 2-session pre- and post-test strategy that is purely informational. One difficulty in conducting randomized trials of behavioral interventions is assuring that the interventions are being conducted both as conceptualized and in a consistent manner by different counselors and, for multicenter studies, at different study sites. This article describes the quality assurance measures that have been used for Project RESPECT. These have included development of standard tools, standard training, frequent observation and feedback to study personnel, and process evaluation.