The collection is large, containing, in addition to printed editions and translations of Heym's books, approximately 300 boxes and volumes of manuscripts, including plot outlines and source studies, and some unpublished literary works. There are also 75 boxes of correspondence (access restricted); some 40 boxes and volumes of press cuttings; 400 audio and 70 video cassettes; and miscellaneous material, such as photographs and wartime pamphlets. The collection is divided into classes as follows:
Class A: Literary manuscripts
These comprise background material pertaining to works by Heym, as well as the works themselves. From the outset Heym typed most of his manuscripts, limiting his handwriting to correction, tables and the rewriting of single paragraphs. The papers include files of sources, either on file cards or photocopied material. There are also contributions from Heym's first wife, Gertrude, including long analyses of his work.
Class B: Texts of interviews
There are sound recordings and texts of interviews. Some of the transcripts were generated by Heym, while others were sent to him by journalists, and were often corrected subsequently by Heym.
Class C: Correspondence
Class D: Press clippings
The initial group of articles concern Heym's literary work, and include some on cultural politics, his political involvement and disputes. From 1989 the emphasis of the articles shifts to Heym's involvement in politics, his literary work from the time of German unification onwards having received comparatively little press attention. Most of the items are cuttings from newspapers and magazines, but there is also publicity material. Certain items are publications of short stories or articles by Heym. Newspaper serialisations of, or excerpts from, various novels are also included. Most of the cuttings are in English or German, but other languages are also used. There is a considerable amount of repetition, with the same article being supplied by more than one source.
Class E: Secret Police files
Class F: Audio material
Audio tapes predominate, mostly private recordings by Heym to ensure that he would be quoted correctly. The quality of recording is poor and frequently incomplete. Most are in German, with some in English and occasionally other languages. The majority are of question and answer sessions following readings or interviews. There are also video cassettes, mostly in German, dating from 1981 onwards.
Class H: Miscellanea
Pamphlets, photographic negatives, slides, photographs, official documents, dust jackets for various works, notebooks, appointment diaries and material concerning Heym's candidacy for election to the German Bundestag in 1994.