Pamphlets, which reflect the times that gave birth to them, are rarely to be found after their brief lives, making them extremely valuable to scholars. In the years since its inception in 1919, the Hoover Library has collected approximately 140,000 pamphlets, making it one of the few institutions in the world to preserve these ephemeral items. Hoover Library's pamphlets cover primarily political and social issues and events, among them the evolution of parties and movements, that shaped our past, though the focus is on the twentieth century. The pamphlets come from all areas of Western and Eastern Europe, Latin America, Africa, the Middle East, and North America. They can truly be considered to be multum in parvo.

The Hoover Library’s pamphlet database describes about 55,000 pamphlets that are not individually described in the online catalog. There are pamphlets in every language--about 33,000 of them are in English, about 10,000 in German, and about 3,000 are in Russian, for example--and of many lengths and illustrative content. The pamphlet database does not include the close to 7,000 pamphlets that can be found in the Hoover Library's card catalog, nor does it include the Institution's estimated 60,000 pamphlets that are yet to be cataloged.

The pamphlets are located in the Hoover Library and are for library use only due to their delicate nature. Copies of these pamphlets are also available on microfilm in the Hoover Library.