The fonds consists of seven series. The first series, personal, consists of Marion Lewis' curriculum vitae. The second series, correspondence, is divided into 4 sub-series. The first sub-series is comprised of various professional and work-related correspondence, both incoming and outgoing, created during the years 1944 through 1996. The correspondence in this series revolves mainly around blood grouping work. The next 3 sub-series revolve around correspondence generated due to an international group Lewis was a part of for many years, the International Society of Blood Transfusion (ISBT). The third series is comprised of records generated by Dr. Bruce Chown. It is divided into two sub-series, the first being chronologically organized correspondence, and the second being research notes. Much of this series is restricted. The fourth series is comprised of reprints of over 140 published articles authored or coauthored by Lewis. The fifth series consists of unpublished articles and lectures given by Lewis throughout her career. The sixth series consists of research done by Lewis when she worked with Dr. Chown. The series is made up of three sub-series. The first contains research done on the blood groups of Hutterites and includes blood group genealogies. The second contains research on Aboriginal and Inuit blood types and contains blood group genealogies, field notes and lists of individuals. The third sub-series consists of miscellaneous research. This series is restricted.

The seventh series is PC 167. It consists of 156 photographs, 468 slides, including 30 glass lantern slides, and a reel-to-reel audio tape. Two of the photos are of Marion Lewis. The rest are photos of individuals whose blood was tested by Lewis and Chown in the 1950s and 1960s. Dr. Chown took most of the slides during a research trip to Alaska in 1960. The majority of them are of Alaskan wildflowers. Lewis used the other slides during her lectures and presentations. Dr. Chown used the lantern slides for research purposes in the 1950s and the reel-to-reel tape was used by Lewis to demonstrate laboratory methods. Some of the photographs are restricted. The eighth series is TC 106. It consists of two mini audiocassettes of a speech given by Lewis.