Community-based conservation (CBC) promotes the idea that conservation success requires engaging with, and providing benefits for, local communities. However, CBC projects are neither consistently successful nor free of controversy. Innovative recent studies evaluating the factors associated with success and failure typically examine only a single resource domain, have limited geographic scope, consider only one outcome, or ignore the nested nature of socioecological systems. To remedy these issues, we use a global comparative database of CBC projects identified by systematic review to evaluate success in four outcome domains (attitudes, behaviors, ecological, economic) and explore synergies and trade-offs among these outcomes. We test hypotheses about how features of the national context, project design, and local community characteristics affect these measures of success. Using bivariate analyses and multivariate proportional odds logistic regressions within a multilevel analysis and model-fitting framework, we show that project design, particularly capacity-building in local communities, is associated with success across all outcomes. In addition, some characteristics of the local community in which projects are conducted, such as tenure regimes and supportive cultural beliefs and institutions, are important for project success. Surprisingly, there is little evidence that national context systematically influences project outcomes. We also find evidence of synergies between pairs of outcomes, particularly between ecological and economic success. We suggest that well-designed and implemented projects can overcome many of the obstacles imposed by local and national conditions to succeed in multiple domains.evidence-based conservation | conservation evaluation | conservation and development | natural resource management A s conservation practitioners seek viable alternatives to strict protectionism, they increasingly recognize that projects must achieve ecological, economic, and social goals to be successful. One class of alternatives includes comanagement and community-based natural resource management and is most easily referred to as community-based conservation (CBC). Although diverse in their details (1), CBC projects typically aim to combine elements that link conservation with development, engage local communities as active stakeholders, and devolve control over natural resources. CBC often promotes the welfare and cooperation of people living in and around areas of conservation interest by providing development opportunities, guaranteeing rights to harvest, emphasizing community involvement and autonomy, and administering payments for ecosystem services. Such approaches have become prominent, especially in the developing world (2-4), as problems associated with protectionism, including human rights infractions (5), high financial costs of protected areas management (6), and difficulty achieving biodiversity conservation without exacerbating poverty (7), became apparent. The rationale is that engaging wit...