Mixed species stands might contribute to important goals of sustainable forest management, such as higher biological diversity, more resistance and resilience to disturbances and higher carbon storage. Knowledge of stakeholders' perceptions of such ecosystem services in mixed species stands is required for effective policy development. We showed that practitioners' and scientists' perceptions of ecosystem services in mixed species stands in Belgium differed from formal scientific knowledge derived from a synthesis of published studies. The positive perception of supporting, regulating and cultural services in mixed species stands contrasted with less conclusive results from the literature, where positive, negative and neutral effects were reported. Many respondents also signified a lack of information about regulating services. Furthermore, provisioning services were perceived as equal in mixed species stands and monocultures, in contrast to higher productivity demonstrated in mixed species stands in the literature. The regional (Flanders and Wallonia) ecological and socio-economic context influenced both the perception of ecosystem services and of the importance of management objectives. Our results highlighted the need to address the lack of scientific data, to adapt communication to the ecological and socio-economic context, as well as to improve information flow on regulating services and productivity. ; Peer reviewed