The nearly 5,000 volumes in the John Martin Rare Book Room are largely original works representing classic contributions to the history of the health sciences from the 15th through 20th Centuries. Also included are selected books, reprints, and journals dealing with the history of medicine at the University and in the State of Iowa. Manuscripts of winning papers written by medical students in competition for the John Martin History of Medicine Prize are also contained in the collection.

Secondary sources such as histories of particular subjects, biographies, and bibliographies are housed in the Hardin Library main collection. Manuscripts, papers, and other documents relating to the history of the University Hospital, basic science departments, and health sciences colleges and programs are maintained in the University Archives at the Main Library, along with personal papers and documents of members of the University community. The Hardin Library does not maintain medical artifacts or instruments in its collections.