The collection consists of contact sheets, approximately 47,000 black-and-white negatives, silver gelatin prints, manuscripts, notebooks, research files, correspondence, pamphlets, and diaries related to a number of published and unpublished photography projects spanning Ulli Steltzer's entire career as a photographer from the late 1950s through 2008, including both her early Princeton portraits and later documentary work. The majority of the collection consists of contact sheets, interleaved with their corresponding negatives, and photographic prints in various sizes, arranged by subject or project. While the majority of negatives are 6x6cm frames of 120 film, some 35mm strips are occassionally present. Most prints in the collection are 8x10" silver gelatin prints, along with a significant group of mounted prints as large as 22x17", as well as occasional smaller formats, slides, and color photographs where noted. Related textual materials accompany photographs, including drafts for books and exhibition catalogs, research notes, travel diaries, interview transcriptions, receipts, bound volumes and pamphlets, and correspondence with publishers, collaborators, and subjects.

Grouped by project, following the chronology of Steltzer's career, the collection includes portraits of prominent Princeton intellectuals, visitors, and their families, including J. Robert Oppenheimer, George McGovern, Adlai Stevenson, Roger Sessions, and Igor Stravinsky; documentary photography depicting migrant workers and urban poverty in New Jersey, Ohio, and Illinois; African American communities and civil rights activists in the South, including the Southern Christian Leadership Conference in 1968; Hopi, Navajo, and Pueblo tribes of the American Southwest; Native American artists of British Columbia, including extensive documentation of the work of Haida carvers Robert Davidson and Bill Reid; the Cakchiquel people of Guatemala; the Inuit of the North American Arctic; immigrants in Los Angeles; India; Lijiang, Baidi, and Yongning, China; and Cuba and Trinidad.