The preponderance of Bulgarian materials in the Library of Congress is held in the general collections. Consisting of thousands of books, journals, and pamphlets, the materials cover all possible subjects with the exception of clinical medicine and technical agriculture, which are collected by the National Library of Medicine and the National Agriculture Library. Materials held in the general collections are findable by searching the Library of Congress Online Catalog.

The largest subject is language and literature. Represented are collected works and individual titles for all of the major Bulgarian authors and poets from all eras, as well as many works of minor writers. There are reprints of old Slavic manuscripts and the works of the Damaskini, scholars who began the transition from religious to secular writing and from using Church Slavic to native Bulgarian. The Library has most of the important dictionaries for Bulgarian such as the Academy dictionary, as well as many smaller, specialized works and historical, etymological, and bilingual dictionaries. Grammars, language textbooks, and linguistic studies are collected extensively.

The history and politics of Bulgaria and the Balkan peoples is a particular strength of the collection. Books on all aspects of Bulgarian history and politics are collected, including the works of all major publishers and contemporary scholars such as Zorka Purvanova, the former First Lady of Bulgaria and Balkan historian - Mezhdu neosushtestveniia khiuriet i neizbezhnata voina : natsionalnite dvizheniia v Evropeiska Turtsiia i mladoturskiiat rezhim 1908-1912 g. [Between the unrealized freedom and the inevitable war: national movements in European Turkey and the Young Turk regime, 1908-1912]. Holdings for the communist era are extensive including the collected works and speeches of major political figures, Todor Zhivkov, Georgi Dimitrov, and Vulku Chervenkov. All of the major historical journals are held such as Izvori za bulgarskata istoriia [Sources for Bulgarian history], Istoricheski pregled [Historical review], and Sbornik za narodni umotvoreniia i narodopis [Collection of folklore and ethnography]. Although many regional materials on history are present in the collection, it is one of the weaker areas. Even today the Library has difficulty acquiring publications from some of the regional cities in Bulgaria. Military history is another weak spot in the Bulgarian collection, with only several hundred titles in the collection.

Recognizing that historians, genealogists, and business researchers frequently need to consult directories, the Library of Congress maintains a collection of international telephone directories. Business and specialized directories from Bulgaria are cataloged and may be identified using the Library of Congress Online Catalog. Uncataloged telephone directories from Bulgaria may be identified using the guide Bulgaria: Address and Telephone Directories. The uncataloged collection contains over 200 volumes from 1936 to 2011. For uncataloged items in the general collections, a researcher must request the items by completing a call slip in the Main Reading Room or asking in person for help in the European Reading Room. Selected directories also have been digitized and are freely available on the Library of Congress website.

The collection is rich in government publications, both historical and current. There are nearly complete holdings of the records of parliament Stenografski dnevnitsi na Narodno subranie [Reports of the National Assembly], Bulgarian census data, and other Bulgarian statistical materials, ranging from the main statistical almanac, Statisticheski godishnik [Statistical annual], to specialty compilations on economics, culture, and agriculture. For more information about the voluminous collection of Bulgarian statistical publications in the Library of Congress, consult Bulgarian Statistics: a Resource Guide.