The effectiveness of HIV voluntary counseling and testing (VCT) in reducing HIV risk behaviors in developing countries was assessed using meta-analytic methods. A standardized protocol was used for searching, acquiring, and extracting study data and meta-analyzing the results. Seven studies met the inclusion criteria. VCT recipients were significantly less likely to engage in unprotected sex when compared to behaviors before receiving VCT, or as compared to participants who had not received VCT [OR 1.69; 95%CI 1.25-2.31]. VCT had no significant effect on the number of sex partners [OR 1.22; 95%CI 0.89-1.67]. While these findings provide only moderate evidence in support of VCT as an effective prevention strategy, neither do they negate the need to expand access to HIV testing and counseling services. Such expansion, however, must be accompanied by rigorous evaluation in order to test, refine and maximize the preventive benefits of learning one's HIV infection status through HIV testing and counseling.