In Phase I, women at each site were randomly assigned to a study arm receiving a community-based male condom promotion intervention, or a study arm receiving community-based male condom promotion supplemented with clinic-based counseling. Randomization was accomplished by the use of sequentially-numbered sealed, opaque envelopes containing the group assignment. The randomization list was stratified by study site. Phase I began with baseline measurement of male condom use and STI prevalence. Participants returned three times, at two month intervals, for follow-up. At each visit, face-to-face interviews were conducted to estimate the proportion of protected sex acts. At the third visit only, participants were tested for gonococcal, chlamydial, and trichomonal infections. This reliance on a combination of biologic and behavioral outcomes helped to reduce any bias brought on by the inherent limitations of either of these measures on its own.