The fonds consists of books, letters, documents, drafts, publications, photographs, and several artifacts collected by W. W. Francis and Marian Francis Kelen over the course of their lifetimes. Many books and documents relate to Sir William Osler and the Osler family including several personal letters, the Deed of Trust documents regarding the Bibliotheca Osleriana, drafts of Osler's works, and a wooden travelling trunk that belonged to Edward Revere Osler. The fonds also includes original poetry written by Marian Osborne, W. W. Francis, and Marian Francis Kelen.

The fonds contains correspondence related to the Osler Library and its holdings with people such as Maude Abbott, Edward Archibald, William B. Bean, Edward Horton Bensley, Archibald Malloch, Casey Wood, as well as John Farquhar Fulton, Keeper of the Medical History Collections at Yale University's library; the fonds also contains a typescript of talks by W.W. Francis (titled "Showman's Patter") about books and other items held in the Osler Library.