Due to their rarity and multiple subtypes, there is scant experience with sarcomas. Any effective targeted therapy depends on precise diagnosis of the tumor group using molecular markers and, increasingly, mutation testing. The necessary histopathological expertise and molecular diagnostic tools are usually only found at specialized centers. Using the Bonner GIST register as an example, the advantages of this kind of register from a diagnostic and therapeutic perspective will be discussed. Material submitted for gastrointestinal stromal tumors and other mesenchymal tumors, as well as the supervision of pathological referencing for national and international studies have made accurate diagnosis and appropriate therapy strategies ever more possible. The introduction of epidemiological as well as interdisciplinary sarcoma registers is a prerequisite for the improvement of sarcoma diagnostics and therapy.