Behavioral interventions have utilized a variety of strategies and components to reduce HIV risk. This article describes the partner intervention, a couple-based group HIV risk reduction intervention implemented in 6 urban community health clinics in Lusaka, Zambia, and examines the components of the intervention and their relationship with condom use. Couple members completed assessments on condom use, acceptability, willingness to use condoms, communication, intimate partner violence (IPV), self-efficacy, and HIV information at baseline and 6 months' follow-up. This study examined the relative impact of elements of the intervention as predictors of condom use. Changes in acceptability had the greatest overall influence on condom use, followed by social support, relationship consensus, and willingness to use condoms. Changes in self-efficacy, IPV, negotiation, and information had no influence. Results support the use of multidimensional approaches in behavioral interventions and highlight the importance of identifying critical elements of interventions to maximize risk reduction outcomes.