Background-Voluntary Counseling and Testing (VCT) continues to play a critical role in HIV prevention, care and treatment. In recent years, different modalities of VCT have been implemented, including clinic-, mobile-and home-based testing and counseling. This review assesses the effects of all VCT types on HIV-related risk behaviors in low-and middle-income countries. Methods-We updated a previous review from 1990-2005 by searching for eligible studies through July 6, 2010 on electronic databases, reference lists, and four key journals. To be included, studies had to evaluate pre-post or multi-arm biological, behavioral, or psychological results from an intervention in a developing country in which participants voluntarily received HIV testing and counseling and were administered pre-test counseling, HIV testing, and post-test counseling. Results-An initial search yielded 2808 citations. After excluding studies failing to meet the inclusion criteria, 19 were deemed eligible for inclusion. Of these studies, two presented duplicate data and were removed. The remaining 17 studies were included in the qualitative synthesis and 8 studies were meta-analyzed. Twelve studies offered clinic-based VCT, 3 were employment-based, 1 involved mobile VCT, and 1 provided home-based VCT. In meta-analysis, the odds of reporting increased number of sexual partners were reduced when comparing participants who received VCT to those who did not, OR= 0.69 (95% CI: 0.53-0.90, p=0.007). There was an insignificant increase in the odds of condom use/protected sex among participants who received VCT compared to those who did not, OR=1.39 (95% CI: 0.97-1.99, p=0.076). When stratified by HIV status, this effect became significant among HIV-positive participants, OR= 3.24 (95% CI: 2.29-4.58, p<0.001).