Postdoctoral researchers play a critical role in scientific research. This is the case not only for the Leibniz Association but for research worldwide. However, postdoctoral researchers are often overlooked or misrepresented as a homogeneous group of researchers. The principal aim of the Leibniz PostDoc Survey was to understand who Leibniz PostDocs are and to provide some insight into their experiences, interests, and needs. This report summarizes the results of the first Leibniz PostDoc Survey, which was open for submission from July to October 2020. The report includes a summary of the key findings and recommendations as well as a comprehensive description of all results from each survey question.