Surgical instrument collections have been used in a multitude of ways – as tools, taxonomies, teaching aids, representation, historical highlights and public displays – and they provide a key to understanding the shifting relations between surgery, medical museums and medical history. Tracing the uses of the surgical instrument collections from the Royal Danish Academy of Surgery and the Medical Historical Museum at the University of Copenhagen reveals a network of disciplinary and institutional changes from the late nineteenth to early twenty-first century. The history of the collections maps relations between scientific and cultural historical collections and between medicine and history. In the same way as surgical instruments have connected the surgeon’s hand to the patients’ body, the surgical instrument collections connect together the public, medical practice and history.