Although there are Russian-language materials peppered throughout all of the reading rooms of the Library of Congress, the European Reading Room maintains custody over a relatively small quantity of material that is nonetheless of critical importance for Russian research. In addition, the European Reading Room is the primary point of contact for researchers interested in materials from and about Russia and its diasporas. The Reading Room manages a collection of over 1,000 reference books both contemporary and "old standards" for Russia, with general encyclopedias, subject encyclopedias, biographical dictionaries, language dictionaries, bibliographies, general surveys, census data, and other reference materials. Due to its size, the Russian reference collection occupies two locations within the European Reading Room, beginning at the front of the reading room and continuing in the reference annex.

Also available in the European Reading Room are most of the Russian newspapers on microfilm, the latest 3 years of unbound periodicals and print newspapers from Russia, specialized microfilm sets, and several ephemera collections. The Reading Room houses the Independent Soviet Press Collection of over 3,000 independent newspapers and serials from the perestroika/glasnost' period, 1987-1992, in both microfilm and print formats. Russian microformat collections are described on the page in this guide devoted to microfilm, but suffice it to say that equipment is available in the European Reading Room for general use such as microfilm scanners, a microfilm reader, a book scanner and a multi-functional printer/scanner.

In the European Reading Room cage a number of unique materials are kept on hand due to rarity or the need for displays. Cage materials include a CIA-funded Russian translation of George Orwell's novel 1984, a samizdat copy of Joseph Brodsky's Ostanovka v pustyne, a smuggling edition of Pushkin's Gavriliada, some unique telephone directories such as a 1940 directory for the Kremlin, and a poster from the early 1990s with original Russian artwork promoting the movie Star Wars. All cage materials are available upon request at the European Reading Room reference desk. Several special collections available in the European Reading Room are described below.

One of the most noteworthy collections is the Rubinov Collection of hand-written Russian letters to the editor from the social issues section of the renowned Russian newspaper Literaturnaia gazeta, circa 1960’s-1980s. Many of the letters concern economic and social problems confronting society in the Soviet Union that could not be addressed officially. The material is stored in 61 archival boxes in the European Reading Room. Another unique collection is the Revelations from the Russian Archives exhibit documents, a collection in photocopy of approximately 600 archival documents from the KGB, Communist Party, Central Committee, Presidential, Kremlin, Foreign Ministry, and other formerly secret Soviet archives. The items, the first ever to be released from the formerly secret archives, were on display at the Library during the Bush-Yeltsin summit in June 1992, and the European Reading Room maintains service copies of all the textual documents included, plus a number of additional Party Archive documents received from other sources (for example, a rare first draft of the Supreme Soviet commission investigating the August 1991 coup attempt).

The European Reading Room also maintains custody of a number of arrearages of interesting retrospective materials (much of this material is now in the process of being cataloged), including early Soviet (1917-1935) periodicals and government serials; pamphlets (including approximately one thousand published before 1865); and Soviet and émigré period monographs that are not found at other American libraries.

Finally, aside from published materials, the European Reading Room holds several historical card catalogs such as one of the Yudin catalogs and the original Slavic Cyrillic Union catalog, and a dedicated terminal for access to the Comintern Archives database.