The primary holdings are extensive collections of original drawings, proofs, and tear sheets of Milton Caniff's comic strips and illustrations, audio/visual materials, correspondence files, business accounts, research files, awards, scrapbooks, and realia. The collection has significant holdings of original art and reproductions of Mister Gilfeather, The Gay Thirties, Dickie Dare, Terry and the Pirates, Male Call, Steve Canyon, and illustrations done for the Columbus Dispatch and the Associated Press.

The Correspondence series includes letters to and from Milton Caniff from fans, cartoonists, business associates, family members, and friends. Also included are correspondence and materials regarding organizations and clubs with which Milton Caniff was associated, publicity materials, and articles by and about Milton Caniff.

The Research Material series includes clipping files from magazines and newspapers, film stills and programs, model airplanes, informational publications, and military items used as reference by Caniff for his comic strips and other projects he undertook such as United States armed forces insignia designs.

The Business Records series contains bank statements, syndicate statements, income tax information, cancelled checks, check stubs, ledgers, bills, expense lists, drafts of wills, subscription notices, and household inventories.

The Photographs series includes photographs of Milton Caniff at chalk talks, in his studio, at personal appearances, at his home, and with organizations, family members, and cartoonists.

The Awards series includes awards, citations, proclamations, and certificates given to Milton Caniff from various organizations.

The Memorabilia and Merchandise series contains personal effects of Milton Caniff, Esther Parsons Caniff, and John Caniff, Milton Caniff's father; merchandise for comic strips Terry and the Pirates and Steve Canyon, and art and office supplies.

The Audio/Visual Material series includes promotion and personal film reels, Steve Canyon television show reels, Terry and the Pirates radio broadcasts, slides, and audio casette tapes.

The Scrapbook series contains scrapbooks with material and artwork for Milton Caniff's 75th birthday, newspaper clippings and publicity, awards and citations, personal photographs, and original artwork by Milton Caniff and Noel Sickles.

The materials in the International Museum of Cartoon Art Collection and Records have been grouped into six series: 1) Proofs, prints and posters 2) Merchandise 3) Organizational records 4) Audio, video, film and floppy media 5) Photographs 6) materials created by animator and artist Wes Herschensohn.

The Proofs, prints and posters include newspaper tear sheets, clippings, comic strip pages aswell as adverts and prints. There are numerous Hal Foster Prince Valiant proofs and tearsheets. Many tearsheets in the collection were taken from the Chicago Tribune, New York Herald, Philadelphia Enquirer, South Bend Tribune, and Sun Sentinel. A number of the posters are for Disney movies.

The Merchandise in the collection is an eclectic mix of cartoon and comics themed collectibles. It includes plastic and ceramic figures, plushes, dolls, bobbleheads, mugs, plates, clothing, banners, board games, and various other realia relating to newspaper comic strip and TV/movie cartoon characters. They have been grouped where there was a significant number of items related to a particular character or strip. These include titles and characters such as Peanuts, Popeye, Garfield, Beetle Bailey, Kilban, Betty Boop, Little Orphan Annie, Nancy, Dick Tracy, Disney and various Superheroes. The merchancise also contains some IMCA related realia.

The bulk of the collection consists of the Organizational Records of the museum and includes correspondence, board of trustees records, financial files including bills and fiscal year reports, human resource records, curatorial and exhibition files, loan information, accession records, biographical files and newspaper clippings. There are files from the early 1990s concerning the constrution and building of the Boca Raton, IMCA building and correspondence relating to the closing of the museum including the Guernsey's catalog of materials sold from the collection in 2001.

The Audio, video, film and floppy media in the collection include over thirty reel to reel audio recordings from the 1950s and 1960s of 'The cartoonist's art' a WRVR syndicated radio show hosted by Vernon Greene. Also included from a similiar time period are twenty recordings of Bill Crawford interviewing contemporary cartoonists. Films include over 600 16mm reels of King Features TV cartoon shows from the 1950s, including; Krazy Kat, Cool McCool, Harry McCool, Popeye, Beetle Bailey & Barney Google.

The collection contains many photographs of the museum, mostly of IMCA at the Boca Raton, Florida location but there are also some of the museum at its Greenwich and Ward's castle locations.

Finally the collection contains hundreds of animation cels and drawings created by Wes Herschensohn for the 1969 movie 'The Picasso Summer' aswell as sketchbooks he created for 'Mikromythos' a proposed project on the life of Beethoven'.