The papers of Sigmund Freud (1856-1939) span the years from about the 6th century BCE to 1998, with the bulk of material dating from 1871 to 1939. The collection documents Freud's founding of psychoanalysis including the birth and maturation of psychoanalytic theory, the refinement of its clinical technique, and the proliferation of its adherents and critics. Many facets of Freud's life and work are featured including his early medical and clinical training; his relationship with family, friends, colleagues, students, and patients; his association with early psychoanalytic societies; his perspectives on analytical training; and his numerous writings. The collection includes family papers, correspondence, holograph and typewritten drafts of writings, patient case files, legal documents, estate records, receipts, military and school records, certificates, notebooks, a pocket watch, a Greek statue, genealogical data, interviews, research files, exhibit material, bibliographies, lists, photographs and drawings, newspaper and magazine clippings, and other printed matter. The papers are arranged in ten series: Family Papers, General Correspondence, Subject File, Writings, Supplemental File, Interviews and Recollections, Additions, Artifacts and Painting, Closed, and Oversize. They are, for the most part, in German, English, and French.

The bulk of the collection consists of original documents, photocopies and other facsimiles, transcripts, English translations, and published editions collected and given to the Library of Congress by the Sigmund Freud Archives. The archives was founded in 1951 by a group of New York analysts, including K. R. Eissler, Heinz Hartmann, Ernst Kris, Bertram David Lewin, and Herman Nunberg, to collect Freud letters and writings which were at risk of being lost or destroyed in the aftermath of World War II. Because Freud did not retain copies of his outgoing correspondence, letters written by him were geographically dispersed among his many correspondents. The archives succeeded in obtaining original Freud material through gifts, most notably Anna Freud's bequest, and through purchase. When unable to acquire original documents, it solicited copies, transcripts, translations, and printed editions.

The Family Papers series contains Freud's correspondence with members of the Freud and Bernays families. Included are exchanges with his mother Amalia Freud, his wife Martha Freud, and their children Ernst L., Martin, Mathilde Freud Hollitscher, Oliver, Sophie Freud Halberstadt, and Anna, the only one of Freud's children to become a psychoanalyst. Among Freud's correspondence with his wife are a series of courtship letters or “brautbriefe” written on an almost daily basis between 1882 and 1886. The letters detail Freud's activities, associations, and aspirations during the period following his graduation from medical school to the establishment of his private practice in Vienna. Extensive correspondence with his sisters, brothers, nieces, nephews, grandchildren, and in-laws reveals the part played by Freud as paternal head of a large and extended family. Among these letters is correspondence between Freud and Minna Bernays, his sister-in-law and close confidante. The series also contains correspondence between individual family members other than Freud as well as correspondence between family members and persons outside the family. Included are letters by several prominent individuals including Princess Marie Bonaparte, Ruth Mack Brunswick, C. G. Jung, and Otto Rank. A subject file containing legal documents, certificates, estate records, school records, writings, and printed matter also relates to Freud's family.

The General Correspondence series features Freud's correspondence with friends, mentors, colleagues, students, and patients spanning seven decades from his school days to his death in 1939. Nearly six hundred correspondents are represented in the series. At times, their correspondence is limited to a single letter to or from Freud. In other cases, the correspondence is extensive, revealing Freud as a prolific correspondent who frequently chastised others for a lack of similar diligence. The earliest of such correspondence consists of Freud's adolescent letters to friends Eduard Silberstein and Emil Fluss while a student at the Leopoldstädter gymansium and the University of Vienna. Freud's subsequent correspondence includes letters from individuals who influenced his early work including Josef Breuer and J. M. Charcot.

The formative years of Freud's psychoanalytic theories is detailed in his correspondence with Berlin physician Wilhelm Fliess. Beginning in 1887 and continuing until just after Freud's break with Fliess in 1902, these letters are among the more revealing in the collection. The series also contains Freud's correspondence with many of his earliest adherents, some of whom also later broke with him. The letters trace the development of a psychoanalytic movement that coalesced around Freud in the years following his break with Fliess. Included is correspondence with Karl Abraham, Alfred Adler, Franz Alexander, A. A. Brill, M. Eitingon, Sándor Ferenczi, Eduard Hitschmann, Ernest Jones, C. G. Jung, Oskar Pfister, Otto Rank, Theodor Reik, Hanns Sachs, Ernst Simmel, Wilhelm Stekel, and Edoardo Weiss, among many others. The Abraham, Brill, Eitingon, Jones, Jung, Pfister, and Reik correspondence includes original Freud letters. Prominent women in the field represented in the series include Lou Andreas-Salmoné, Ruth Mack Brunswick, Emma Eckstein, Jeanne Lampl-de Groot, and Joan Riviere. Princess Marie Bonaparte's correspondence with Freud is located in her papers in the Manuscript Division. Notable among Freud's patients with whom he corresponded is Sergius Pankejeff whom Freud referred to as the “Wolf-Man.” Other prominent correspondents include Albert Einstein with whom Freud corresponded on the nature of war, Carl Koller who shared Freud's interest in the medical uses of cocaine, and novelist and essayist Thomas Mann.

The Subject File series includes patient case files from the Allgemeines Krankenhaus in Vienna and the Bellevue Sanatorium in Kreuzlingen, Switzerland, largely during the 1880s. Copies of book annotations and marginalia by Freud provide glimpses into the development of his theories. His career is highlighted in a large file of newspaper and magazine clippings as well as material concerning the Goethe Prize he received in 1930 and the Nobel Prize which he coveted but never received. Calendars kept by Freud record his daily activities from 1916 to 1918. Freud's early life is documented by biographical data, birth and marriage certificates, and gymnasium, university, and military records. His departure from Nazi-controlled Austria and immigration to London in 1938 is tracked through American diplomatic cables and newspaper clippings. The series also contains letters and telegrams written on his death just over a year after his arrival in England.

The Writings series contains holograph and typewritten drafts, galley proofs, offprints, and published copies of many of Freud's writings. Because of the large format of many of these items, the material has been filed in the Oversize series. The writings range chronologically from an 1877 article on his early research on eels to portions of his last major work, Der Mann Moses und die monotheistische Religion, published shortly before his death. Included in the series are articles, case histories, portions of books, published letters, lecture notes, prefaces, introductions, a travel journal, chronologies, obituaries, bibliographic notes, and casual jottings. The writings are arranged and described largely according to the bibliographic sequence established by James Strachey in Indexes and Bibliographies , volume 24 of The Standard Edition of the Complete Psychological Works of Sigmund Freud (London, 1974) and, for works published after 1974, by Ingeborg Meyer-Palmedo and Gerhard Fichtner, Freud-Bibliographie mit Werkkonkordanz (Frankfurt am Main, 1989).

The Supplemental File series consists of material about Freud's life and work written or collected by Freud associates and scholars. The bulk of the material dates after Freud's death. Apart from articles and other writings, the series includes material related to observances in 1956 of the centenary of Freud's birth; Norman Kiel's compilation of contemporary and posthumous reviews of Freud's published works; and a medical file comprising correspondence, notes, and case histories by Hans Pichler and Max Schur relating to Freud's illness with cancer. Lists and research guides include Gerhard Fichtner's bibliographies, chronologies, lists, and inventories of Freud's correspondence and writings. Also included are auction catalogs listing the sale of Freudiana and lists of Freud's lectures and students at the University of Vienna. Miscellany at the end of the series consists primarily of printed matter including a clipping file dated largely between 1954 and 1979 which traces scholarly and popular treatment of Freud in the decades following his death.

The Interviews and Recollections series was compiled by K. R. Eissler, a founder and longtime secretary of the Sigmund Freud Archives. Hundreds of Eissler's interviews with Freud's associates, patients, and family are included in the series, most of them conducted in the 1950s. The series contains transcripts, some with corrections by the interviewee, and summaries of interviews, usually made when the subject requested that the interview not be tape recorded. Audio recordings that were made have been transferred to the Library's Motion Picture, Broadcasting, and Recorded Sound Division. Among those interviewed by Eissler are family members Anna Freud Bernays, Anna Freud, Ernestine Drucker Freud, Harry Freud, Oliver Freud, Judith Bernays Heller, and prominent associates such as Franz Alexander, Ludwig Binswanger, Felix Deutsch, Eduard Hitschmann, Edith Banfield Jackson, Ludwig Jekels, Sergius Pankejeff, Oskar Pfister, Theodor Reik, Joan Riviere, Philipp Sarasin, Hermann Swoboda, and Edoardo Weiss. Also included in the series are recollections about Freud contained in letters, writings, and notes either addressed to or collected by Eissler.

Artifacts in the collection consist of Freud's pocket watch which he gave to his personal physician Max Schur and a small Greek statue which Freud kept on his desk and later gave to Angelika Frink. The collection also includes an oil portrait of Freud.

An Additions series consists largely of supplemental material added to the collection in 2010. Included are photographs, wall text, and captions from exhibits commemorating the centenary of Freud's birth and an index to the standard edition of Freud's works. Files from the work of Herman and Margarete Nunberg include a history of the "Rat man" case and English translations by Margarete Nunberg of Freud's correspondence with Princess Marie Bonaparte, René Laforgue, and others. Photocopies of Freud's correspondence with writer Arnold Zweig, which were derestricted in 2010, are also present. The legibility of the photocopies varies considerably. A 2019 addition includes a letter from Freud to Paul Federn in 1913, in which he outlines his life history, and letters from Freud to Heinz Hartmann, 1927-1939, copies of which are in the General Correspondence series.