Who are the beneficiaries from participative approaches in conservation? The authors compare two protected areas Amarakaeri Communal Reserve in Peru and Selous Game Reserve in Tanzania and show how in similar institutional settings local interest groups react very differently to the possibility of participation. The difference, however, does not regard economic benefits. In the case of Peru, local groups defining themselves as indigenous peoples see a political gain in participatory conservation, which seems to offer the possibility for securing land rights in their area. In Tanzania, however, local actors oppose participative conservation strategies or passively resist those forced on them because they cause high-economic costs and no political gains. By comparing both cases based on a new institutionalism analysis, the article reveals how intended and unintended costs and benefits can explain different attitudes of local groups to participative conservation.