Understanding why people make the decisions they do remains a fundamental challenge facing conservation science. Ecosystem service (ES) (a benefit people derive from an ecosystem) approaches to conservation reflect efforts to anticipate people's preferences and influence their environmental behavior. Yet, the design of ES approaches seldom includes psychological theories of human behavior. We sought to alleviate this omission by applying a psychological theory of human values to a cross-cultural ES assessment. We used interviews and focus groups with fish workers from 28 coral reef fishing communities in 4 countries to qualitatively identify the motivations (i.e., human values) underlying preferences for ES; quantitatively evaluate resource user ES priorities; and identify common patterns among ES motivations and ES priorities (i.e., trade-offs and synergies). Three key findings are evident that align with human values theory. First, motivations underlying preferences for individual ESs reflected multiple human values within the same value domain (e.g., self-enhancement). Second, when averaged at community or country scales, the order of ES priorities was consistent. However, the order belied significant variation that existed among individuals. Third, in line with human values theory, ESs related to one another in a consistent pattern; certain service pairs reflected trade-off relationships (e.g., supporting and provisioning), whereas other service pairs reflected synergistic relationships (e.g., supporting and regulating). Together, these findings help improve understanding of when and why convergence and trade-offs in people's preferences for ESs occur, and this knowledge can inform the development of suitable conservation actions.