This collection consists chiefly of manuscripts and correspondence of Arcadio Díaz Quiñones. Some of the manuscripts of Díaz Quiñones are transcripts of unpublished interviews with writers. Included are the autograph and typescript manuscripts of his interviews with Luis Rafael Sánchez (partially published in the journal Sin Nombre [San Juan, P.R.], 1981), and Cintio Vitier (published as Cintio Vitier, la memoria integradora [San Juan, P.R.: Editorial Sin Nombre, 1987]). The bulk of the collection is made up of correspondence, predominantly between Díaz Quiñones and Puerto Rican and Cuban writers, but there are also letters from writers, artists, and scholars from other Latin American countries, Spain, and the United States, as well as from former students. Correspondents in the collection include Ricardo Piglia, Ángel Rama, Joseph Sommers, Rosario Ferré, Edwin Figueroa, José Luis González, Lorenzo Homar, René Marqués, Antonio Martorell, Ángel G. Quintero Rivera, Nilita Vientós Gastón, Ambrosio Fornet, Fina García Marruz, and Cintio Vitier. Notable as well is the correspondence with the Centro de Estudios de la Realidad Puertorriqueña (CEREP) and the Asociación Puertorriqueña de Profesores Universitarios (APPU). Also present is a small amount of printed materials, including event fliers and programs, and a copy of a map annotated by Argentine author Juan José Saer.

Furthermore, the collection contains a selection of works by others that were sent to Díaz Quiñones. These manuscripts include the writings of the Puerto Ricans Vanessa Droz, Rosario Ferré, Lorenzo Homar, José Luis González, René Marqués, and Luis Rafael Sánchez, and Cubans Víctor Fowler and Fina García Marruz.

The following standard abbreviations, or their variations, are used to identify materials in this collection: ALS = autograph letter signed, TLS = typed letter signed, ACS = autograph card signed, AMsS = autograph manuscript signed, and TMsS = typed manuscript signed.