This paper describes the intervention design and implementation and presents the baseline findings of a Cluster Randomized Controlled Trial (RCT) of a two-year, theory-based community-mobilisation intervention that aimed to change gender norms and reduce HIV risk in rural Mpumalanga province, South Africa. It is among the first community approach RCTs to evaluate a gender transformative intervention, which should increase the potential for impact in desired outcomes and be useful for future scale-up if proven effective.