The incidence of HIV/AIDS in India is increasing drastically, and truck drivers are seen as critical sources of HIV transmission due to their high rates of unprotected sex with multiple partners. An intervention based on the Information-Motivation-Behavioral Skills (IMB) model was compared to an information-only control condition in a randomized trial. IMB constructs were assessed among 250 male truck drivers immediately prior to and following implementation of the intervention, and sexual and condom use behaviors were assessed approximately 10 months later. The intervention consisted of a single-session group workshop with 5 interactive activities designed to address HIV prevention-related IMB constructs and to motivate condom use. Findings showed mixed support for the effectiveness of the intervention. There was an effect of the IMB intervention on attitudes, norms, behavioral skills, and intentions specific to condom use with marital partners, but no effects on constructs related to non-marital partners. There was some evidence of greater condom use with marital and non-marital partners at behavioral follow-up for participants in the IMB condition, and effects on condom use with marital partners were mediated by changes in IMB constructs. These findings provide initial evidence for the effectiveness of theoretically-based approaches to HIV prevention in India.