Participatory policies for natural resource management and poverty reduction have been implemented worldwide. Inclusive participation and empowerment potentially enhances intrinsic motivation to conserve resources. However, whether participation in activities for poverty reduction enhances intrinsic motivation for resource conservation is unknown. We evaluate the impact of participation, in activities to develop sustainable livelihoods, on the intrinsic motivation of forest-dwelling community members to conserve forest commons. As a component of Brazil’s Bolsa Floresta programme, these activities involve decision making, skills training and knowledge exchange related to sustainable livelihoods. Using a framed common-pool resource game with 160 community members in Amazonas State, we measure intrinsic motivation via members’ extent of cooperation in conservation of trees.