Community involvement is increasingly identified as a “critical enabler” of an effective HIV/AIDS response. We explore pathways between community participation and HIV prevention, treatment and impact mitigation in Zimbabwe, reviewing six qualitative studies in Manicaland. These find that community group membership is often (not always) associated with decreased HIV incidence, reduced stigma and improved access to some services, particularly amongst women. Participation in formal community groups (e.g., church or women's groups) and informal local networks (e.g., neighbours, families) provides opportunities for critical dialogue about HIV/AIDS, often facilitating renegotiation of harmful social norms, sharing of previously hidden personal experiences of HIV/AIDS, formulation of positive action plans and solidarity to action them. However, implementation of new plans and insights is constrained by poverty, social uncertainty and poor service delivery. Furthermore, dialogue may have negative effects, spreading false information and entrenching negative norms. The extent that formal groups and informal networks facilitate externally imposed HIV/AIDS interventions varies. They potentially provide vital practical and emotional support, facilitating service access, treatment adherence and AIDS care. However, they may sometimes play a negative role in prevention activities, challenging stereotypes about sexuality or gender. There is an urgent need for greater recognition of the role of indigenous community groups and networks, and the inclusion of “strengthening local responses” as a key element of interventions and policy. Such efforts require great sensitivity. Heavy-handed external interference in complex indigenous relationships risks undermining the localism and bottom-up initiative and activism that might be central to their effectiveness. Cautious efforts might seek to enhance the potentially beneficial effects of groups, especially for women, and limit potentially damaging ones, especially for men. Efforts should be made to facilitate contexts that enable groups to have beneficial effects, through nesting them within wider comprehensive responses, and supporting them through strong partnerships with service providers.