This category includes master's theses, doctoral and post-doctoral dissertations, inauguraldissertationen and habilitationschriften.

Academic dissertations, including theses and postdoctoral dissertations, played an important role in communicating results of original biomedical research before the rise of commercial scientific publishing. The Library's historical collections are rich in dissertation literature, and NLM continues to collect historical dissertations.

Although most present-day Western clinical and scientific dissertation research is reported elsewhere in the scientific literature or provides secondary review of research literature, the dissertation literature remains an important source of original research in some fields, such as the history of medicine, medical anthropology, and paleopathology. Dissertations from less developed countries also are of interest, not only because they report research not documented elsewhere, but also because they may contain unique cultural and regional perspectives. NLM selectively collects modern dissertations, with emphasis on those that contain significant primary research not likely to be reported in other literature held at the Library and those from countries that produce little biomedical literature.