OBJECTIVE: Assess the cost-effectiveness of an intervention combining microfinance with gender and HIV training for the prevention of intimate partner violence (IPV) in South Africa. METHODS: We performed a cost-effectiveness analysis alongside a cluster-randomized trial. We assessed the cost-effectiveness of the intervention in both the trial and initial scale-up phase. RESULTS: We estimated the cost per DALY gained as US$7688 for the trial phase and US$2307 for the initial scale-up. The findings were sensitive to the statistical uncertainty in effect estimates but otherwise robust to other key assumptions employed in the analysis. CONCLUSIONS: The findings suggest that this combined economic and health intervention was cost-effective in its trial phase and highly cost-effective in scale-up. These estimates are probably conservative, as they do not include the health and development benefits of the intervention beyond IPV reduction.