The Henry Mancini Papers span the 1930s through the 2000s, the bulk of which date from 1957 to 1995. The materials relate to the life and works of composer, arranger, pianist, and conductor Henry Mancini, collectively offering insight into his entire career, from his earliest musical training to his final activities as a composer and conductor and subsequent recognition following his death in 1994.

The Music series accounts for approximately eighty five percent of the collection and is divided into six subseries. The first three subseries include scores, parts, and sketches for most of his award-winning projects. Notable projects in the Music for Films subseries include the parts for The Glenn Miller Story (1954), Jack Hayes's original orchestration of the main theme from The Pink Panther (1963), and Mancini's original scores for the film Breakfast at Tiffany's (1961). The Music for TV subseries contains scores and parts for all 114 episodes of the hit series Peter Gunn (1958-1961), making it the largest project in the Music series. The Music for Recordings subseries contains parts and scores for most records, singles, and albums devoted to Mancini's music released during his lifetime. The Concert Music subseries includes music performed at concerts, ceremonies, and other events, many of which featured Mancini as conductor. A small subseries of Other Music materials contains a variety of works composed for unspecified projects or for use in another medium of performance, such as theater. Most notable are the voluminous materials for the stage production Victor/Victoria: The Musical . The Music by Others subseries includes arrangements of Mancini's works, mostly written by fans; new pieces by amateur composers seeking Mancini's input; works by notable composers and lyricists, such as John Williams; and several original holograph scores by David Rose.

The Project Files series contains materials related to a number of Mancini's film, television, and recording projects dating from 1953 to 1995. These files include correspondence, publicity sheets, schedules, financial records, and other miscellaneous materials specific to the creation and evolution of each project.

The Business Papers series includes documents regarding the management and function of Henry Mancini Enterprises, its subsidiaries, and associates. Among these items are contracts, legal papers, other financial records, and travel paperwork. In addition, this series highlights Mancini's work with the American Society of Composers, Authors and Publishers (ASCAP) and other artistic and musical organizations.

The Photographs series consists primarily of images dating from about 1950 through 2004. Included are images of Mancini alone or with other notable figures in candid settings, as well as rehearsals and performances, slides and cuttings from the original film reel of Romeo and Juliet (1964), family photographs, and individual shots of Ginny Mancini.

Personal correspondence with Henry and Ginny Mancini dating from the 1950s to 1995 comprises the Correspondence series. The types of items represented in this series include fan mail, birthday cards, congratulations letters, get well cards, invitations, and condolence letters. Correspondents are largely political figures, actors, record and film producers, and others active in the performing arts.

The Scripts series contains scripts for films, television shows and specials, concerts, and stage productions that involved Mancini as either composer or honoree. While the majority of these scripts are for completed projects, some are associated with unfinished efforts for which Mancini never composed any music.

The Writings series, spanning from 1940 to 2000, is divided into two subseries: Writings by Mancini and Writings about Mancini. The former includes drafts for Mancini's book on orchestration, his autobiography, and his column in Down Beat magazine. The latter features full-length magazine articles and published interviews.

The Programs series includes programs for concerts and events from 1960 to 2009 in which Mancini is credited as conductor, composer, or honoree.

The Promotional Materials series includes press releases and other advertisements for Mancini's films, television series, recordings, and concerts. It also contains a poster-sized version of Henry Mancini's 2004 commemorative postage stamp.

The Scrapbooks series consists of five scrapbooks that document significant moments in Mancini's professional and private life between 1958 and 1984. These contain photographs, clippings, correspondence, programs, and other materials for a variety of subjects and events, including Peter Gunn and a 1967 tour of Japan.

The Clippings series contains magazine and newspaper clippings dating from 1934 to the 2000s. These items document Mancini's family life, film and album reviews, awards and accolades, charity and outreach engagements, and his continued legacy after his death.

The Biographical Materials series consists of items related to Mancini's personal life, such as yearbooks, military papers, his mother's journal, and awards. Papers and awards related specifically to Ginny Mancini are also located here.

The Realia series includes autograph cards, stationary, press passes, and ticket stubs dating from 1954 to 2005. It also contains one of Mancini's CD albums that was played in outer space, a ticket sale plaque from Radio City Music Hall, and Academy Award Nomination plaques.

The Miscellany series includes lyrics for a song for Mancini’s 64th birthday, guestbooks from his funeral, Lawrence Miller’s poem "Perfect," and other assorted items.