This article looks at what happens when volunteering goes well. It provides a theoretical and empirical grounding for understanding how volunteers enable outcomes such as participation and cooperation in complex change environments. The findings point to three important qualities of volunteer relationships, which alter how people feel about themselves, others and their situation: informality, the act of doing together and networked reciprocity. When these relational styles foster three psychosocial experiences known to support human wellbeing – relatedness, competency and autonomy – they make it possible for marginalised and poor groups to participate, initiate and share ownership in the change process. When socially as well as personally rewarding, volunteer relationships can also strengthen solidarity, a knowledge of other's strengths and social commitment, strengthening the basis for social action to continue as a cooperative process with other people. Implications for how volunteering is utilised and strengthened as a strategy for community development are discussed.