A global consensus now recognises biodiversity as equal to climate change in its importance to sustainable development. While multilateral development banks (MDBs) have developed a strong emphasis on climate change, how do they approach biodiversity as a new priority? Current literature on MDBs' approach to climate change is prolific, but scholarship on biodiversity is scarce. Here, we compare MDBs' climate and biodiversity efforts in order to identify differences, analyze causes, and ultimately propose ways for MDBs to prioritise biodiversity. Methodologically, we analyze MDB documents in the form of policies, high‐level announcements, and strategies, in order to compare climate change and biodiversity across five aspects: Financing, policy, strategy, client requirements, and environmental reporting. Subsequently, we apply automated text analysis to examine mentions of climate change and biodiversity in annual reports. Focusing on the 10 largest MDBs, we find that across all five aspects, MDBs' prioritisation of biodiversity lags far behind that of climate change. From that, we recommend that biodiversity be prioritised by MDBs in three ways: By adopting an integrated strategic approach to environmental issues that goes beyond climate, by not only addressing biodiversity through safeguards but also through labeled projects, and by assigning targets as proportions of total financing. [ABSTRACT FROM AUTHOR]