The Sir William Osler Collection, distinct from the Bibliotheca, is an extensive archival holding of Osler's correspondence (including eighteen hundred original letters), daybooks, accounts, engagement books, legal documents, book invoices, membership certificates, notebooks, lectures, addresses, newspaper clippings, photographs, books with manuscript additions, and miscellaneous loose items formerly inserted into individual books in his library. The collection also contains various family papers, including correspondence of Lady Grace Revere Osler and Edward Revere Osler.

Fonds consists of chiefly correspondence of or about Dr. John Clarence Webster, from 1892 to 1952. It also contains his medical thesis from 1891, "Tubo-pentoneal ectopic gestation. The anatomy of the pelvis during the puerperium, and the female pelvic floor,"with accompanying 2 bound volumes of watercolour plates.

Fonds documents Charles Ferdinand Martin's activities during his career at McGill University. The fonds contains correspondence, newspaper clippings, manuscript and typescript addresses.

The fonds documents Dr. McNally's work in otolaryngology and his lecture notes by Harold S. Dolan, M.D., Dalhousie, 1923.

Fonds shows Dr. D. Sclater Lewis' medical and medical-historical activities, from 1904 until his death. The fonds contains correspondence, lecture notes and notes for addresses and published papers.

Fonds documents Dr. H.E. MacDermot's medical-historical activities. The fonds contains newspaper clippings, manuscript notes, photographs, lectures notes, and a draft of The MGH, the Years of Change.

Fonds documents Dr. J.C. Meakins' professional activities.

The content of the fonds includes letters, photographs, and official documents surrounding the Norman Bethune McGill-China Professorship Exchange at Peking Medical College, in addition to medical pamphlets, typed addresses, several commemorative Norman Bethune items. There are various Chinese tourist brochures and maps that McGregor collected during his travels in China, as well as newspaper clippings, reprints, and copies of articles collected by McGregor about China and medicine in the mid-1970s.

The collection contains private records and papers relating to the medical and teaching career of Maude Abbott. It consists in large part of correspondence, 1894-1920, including family correspondence with, among others, her sister Alice Abbott, 1904-1919, and her brother Rev. Harry M. Babin, 1916-1920. Also included are manuscripts and drafts of articles and addresses; case reports; post-mortem records; glass slides and drawings; exhibit panels largely pertaining to her research on congenital heart disease; programmes of medical meetings, 1902-1937; reprints and papers relating to the history of medicine in Montreal and Quebec, as well as to the history of McGill, 1829-1936. In addition, there are photographs, some poems, an autobiographical sketch and a printed copy of her Classified and Annotated Bibliography of Sir William Osler's Publications, 1939, with corrections and annotations by W. W. Francis. Fonds also includes a draft of Abbott's letter to the Dean of Faculty of Medicine, McGill University, regarding admission (1889).

Fonds documents Dr. Alton Goldbloom's professional activities, mainly his writings on pediatrics. The fonds contains diplomas, notice of appointment, correspondence, notes, reprints, manuscripts of I'm on Your Side, Small Patients, and revised text of Le soin de l'enfant.