The World Network of Biosphere Reserves promotes learning sites for sustainable development, designated under the UNESCO Man and the Biosphere programme (MAB). The programme aims to strengthen biodiversity conservation, economic development and capacity building. Scientific research in and about Biosphere Reserves is expected to support these objectives. In response to a strong focus on natural sciences and conservation issues, calls for transdisciplinary approaches emanated from science and the newest MAB Lima Action Plan. Yet, the extent and contributions of transdisciplinary research in Biosphere Reserves remains unexplored. This study provides a comprehensive and systematic screening of 3304 scientific publications in and about Biosphere Reserves published since 1975. Research within Biosphere Reserves spans a broad spectrum, encompassing social to political to ecological investigations, with a focus on natural sciences and studies conducted mainly in Europe and Asia. We identified an emerging field of transdisciplinary science in research, represented in 336 publications. Most transdisciplinary studies were conducted in Mexican and Indian Biosphere Reserves. While transdisciplinary research provided insights about participation, management and governance in Biosphere Reserves, its transformative potential could be enhanced, notably through stronger forms of participation of non-academic actors in research processes. Our review suggests strengthening knowledge co-creation about transformative solutions and interventions addressing deep leverage points. Scientific research could thereby enhance the role of Biosphere Reserves as model regions for sustainability transformations.