A growing body of evidence suggests that programs seeking to change harmful gender norms can have notable HIV-related impacts on program participants, including increased condom use, and a decrease in STIs and intimate partner violence. Yet there is limited evidence of whether such programs can shift norms at the community level, and if so, whether, and how, these changes can improve men’s and women’s uptake of HIV services. Project SOAR and partners are addressing these knowledge gaps by building on an ongoing National Institute of Mental Health-funded randomized controlled trial being conducted in South Africa—Community Mobilization for Treatment as Prevention. Specifically, we are strengthening and expanding the gender content of the intervention to engage both women and men in critically examining gender norms and power inequalities. We are also examining the intervention’s effects in changing community gender norms and resulting HIV service utilization. This study is particularly timely as it will address a key question in the field as to how gender norms may operate to affect HIV service utilization. Building the evidence base in this area is vital for improving care outcomes as well as creating more equitable gender norms, a gateway variable to a range of positive HIVrelated behaviors. There is also a need to better understand these relationships in South Africa, given its generalized HIV epidemic and high levels of gender-based violence.