Gender-based violence is a global problem, but little rigorous research exists on the effectiveness of interventions that aim to reduce and prevent such violence. Violence is the result of the complex interplay of several factors, including social norms and attitudes. In Peru, researchers are partnering with the government to provide training to local leaders to become community health volunteers and to work with their communities and key stakeholders towards shifting attitudes regarding gender, work with their communities at various levels, and increase skills to detect women at risk. They will evaluate the impact of this training on the incidence of gender-based violence and on women’s physical and mental health.