The Alan Klein Papers are a part of the Downtown Collection at the Fales Library, New York University. The Fales Library is the primary special collections division of the NYU Libraries, housing nearly 200,000 volumes of English and American literature from 1700 to the present. Strengths of the collection include the development of the English and American novel, with an emphasis on the Gothic and the Victorian novel, and the post-1975 Downtown New York scene.

The Alan Klein Papers are a diverse collection of materials, including correspondence, fact sheets, flyers, healthcare reports, minutes, periodicals, press clippings, T-shirts and other materials, which collectively document the activities of Act Up (AIDS Coalition to Unleash Power) and Queer Nation, as well as the social and political issues central to their causes. Throughout the processing of these papers, Klein's original folder groupings and titles were maintained as much as possible. These folders were then filed alphabetically under the series titles Act Up, Queer Nation, AIDS, and General Files based on the content of their materials.