Protected areas are considered key to conserving ecosystems and safeguarding biodiversity worldwide. Local stakeholders’ involvement in decision-making in area-based conservation approaches may help to mitigate environmental inequalities and to improve social and ecological outcomes. However, sound and in-depth evidence on the relationship between participation and protected area outcomes is piecemeal. To synthesize the available knowledge, we provide evidence from a systematic literature review of 52 empirical case studies from the scientific literature examining the social and ecological outcomes of protected-area-related decision-making processes in which local stakeholders participated. In a first step, we defined factors that are linked to social and ecological protected area outcomes as success. Based on these factors, we then categorized success indicators which we quantitatively linked to features of participation. Our review provides evidence of the relationship between protected area successes and the following four features of participation: 1. Genuine devolution of power to the local level; 2. Involvement of diverse actors and multiple perspectives through fair and inclusive processes; 3. Long-term external support; 4. Devolution of rights. Even though the degree and form of participation require adjustment to specific local contexts, this overview of features provides sound evidence based on the relation between participatory decision-making and social and ecological effectiveness in protected areas. These insights can be used to design more effective participatory conservation interventions that meet both biodiversity conservation and human well-being.