The Moe Berg Papers consists of typed and hand-written correspondence, hand-written notes loose or in notebooks or notepads, silver gelatin photographs of varying size, and miscellaneous and printed materials such as newspaper clippings, financial information, and materials on Berg collected by others. Languages in the collection include French, German, Japanese, and Italian.

Correspondence makes up the physical and intellectual bulk of the papers and relates mainly to Berg's time with the Office of Strategic Services. Most of the materials are carbon-copies of typed letters and documentation exchanged back and forth by government pouch during World War II. Drafts of cables, official orders, and scientific documentation acquired for or during Berg's many assignments are also present. Notable correspondents include Nelson A. Rockefeller, Vannevar Bush, and General Leslie R. Groves.

Berg also took copious notes from the 1930s through the 1960s in a variety of formats. Some notes relate directly to his government work. Others keep track of his social life, consisting of a vast network of friends in baseball, government and law, and society on the East Coast. Berg's continued interest in academics resulted in notes on books and linguistics. Later notes contain autobiographical accounts or remarks on his past.

A number of black-and-white photographs are included and relate to the things most commonly associated with Moe Berg: his baseball career, pre-war trips to Japan, experiences abroad during World War II, and his relationships with friends and family. Along with snapshots, there are professional press images, copy-prints from the 1980s for which the originals are not present, and many duplicates of images Berg himself favored. Notable individuals include baseball players Babe Ruth, "Lefty" O'Doul, Joe Cronin, Hollis Thurston, and physicist Paul Scherrer.

Finally, the Moe Berg Papers contain printed material, such as ephemera Berg collected abroad and newspaper clippings covering his baseball career, as well as materials collected posthumously by others on Berg. There is also financial information spanning most of Berg's active adult life.

This collection is arranged into five series with additional subdivisions.