The Arnold Sundgaard papers includes materials created and collected by Arnold Sundgaard. The collection is divided into eight series: Correspondence; Musical Scores; Newspaper Clippings; Photographs; Playscripts; Programs and Posters; Writings, Reviews, Publications; and Audio Recordings. Series are primarily arranged alphabetically by material type and then alphabetically by folder title. Series eight, Audio Recordings, is arranged by size of material.

Series 1: Correspondence, is arranged alphabetically by play title, organization or person. Plays written about include Akron by Moonlight, Down in the Valley, The Beautiful and Anxious Maidens, Equinox, Everywhere I Roam, Forests of the Night, Giants in the Earth, The First Crocus, The Great Campaign, The Kilgo Run, Knock on Wood, and Nobody's Earnest. Persons and organizations included in the correspondence are: The Atlantic Monthly, George P. Baker, Yale, The Barter Theatre, Louis Bellson, Bing Crosby, Lehman Engel, Archibald MacLeish, The New Yorker magazine, Gregory Peck, E. B. White, Alec Wilder, and Thornton Wilder among others.

Series 2: Musical Scores, is arranged alphabetically by title and comprises sheet music and lyrics written by Arnold Sundgaard. Some of the music is published under title of play and some are handwritten music for individual songs. Plays included are: Buddy, Knock on Wood, Of Love Remembered, Promised Valley, Cumberland Fair: A Jamboree, Down in the Valley, Gallantry, Sunday Excursion, The Lowland Sea, The Lonesome Dove. About one-third of the material is in oversize boxes.

Series 3: Newspaper Clippings, is arranged alphabetically by title and includes primarily newspaper and magazine clippings relating to play productions and writings authored by Sundgaard, as well as scrapbooks, programs, ephemera, and some photographs. Two scrapbooks, one about Of Love Remembered, the other about Federal Theatre Project productions, Spirochete and Everywhere I Roam, are housed in oversize boxes.

Series 4: Photographs, is arranged alphabetically by title and includes photographs of play productions, actors, and Arnold Sundgaard. Photographs of play productions include the plays: Brigham, Down in the Valley, Equinox, Everywhere I Roam, Forests of the Night, Giants in the Earth, The Great Campaign, The First Crocus, Kilgo Run, Knock on Wood, Of Love Remembered, The Promised Valley, Spirochete, This Fallow Ground, and The Truth About Windmills. Images are mostly prints; there are some slides, and some oversize material.

Series 5: Playscripts, is arranged alphabetically by title and includes primarily playscripts but also radio and television scripts, libretti, outlines, drafts, production notes, scores, programs, costume designs, and some correspondence. Multiple drafts of produced plays are here, as is unfinished scripts and scripts for plays not produced.

Series 6: Programs and Posters, is arranged alphabetically by title and includes programs and posters for productions written by Sundgaard as well as programs collected by Sundgaard.

Series 7: Writings, Reviews, Publications, is arranged alphabetically by title and includes writings by Sundgaard that are not scripts. The writings include drafts, outlines, articles, essays, and short stories. Both unpublished and published material is included. There are some books. Also present is research material created by Sundgaard for different projects. One project was a syphilis related research project for a possible book that Sundgaard undertook with O.C. Wenger. Another project represented is research of deafness conducted by Sundgaard in Hermann, Missouri.

Series 8: Audio Recordings, is arranged by size and consists of four boxes that include audio cassette tapes, reel-to-reel audio recordings, and vinyl records. The material includes recordings from productions or songs that Sundgaard wrote, and records featuring Sundgaard's children's books.