After founding of the Library, its collections were formed from gifts received from foreign universities and foundations, as well as individuals. When moving into a newly built building, the collection contained 57,254 volumes. Until World War II, the collection development was based on the legacies, reparations from Germany and purchasing the important scientific and cultural works, and the acquisition of manuals and textbooks that were necessary for Library users. Before the Second World War the collection contained 318,772 volumes.
Since the National Library of Serbia was destroyed during the German bombing on April 6, 1941, the University Library had been receiving the sample copy of any book published in Serbia from October 1944 to 1963. A number of gifts were received, the inter-library loan began with many academic libraries in the country and abroad, and due to a continual funds for the purchase of books the collection was greatly enriched. Until the liberation the acquisition was mainly focused on publications in the field of social sciences in French and German, but later the acquisition policy re-focused to all scientific fields and all languages. At the beginning of the new millennium, the collections have grown to over 1.5 million volumes. Library's storage holds capital works from all scientific fields, a large collection of local and foreign manuals (encyclopedias, bibliographies, dictionaries), professional and scientific journals, local and foreign university publications, and a rich collection of textbooks and important domestic and foreign doctoral dissertations.
The serials collection contains more than 8,500 titles, i.e. 700,000 volumes. About 5,200 foreign serials are mostly in English, German, French and Russian. Because of financial difficulties in serials acquisition, the greater part of this collection is acquired through exchange and gifts. Since 2000, the Library has a license for EBSCO, which includes a database with thousands of electronic journals in full text in the field of social sciences and medicine. Serbian consortium for coordinated acquisition of electronic resources (KoBSON) was formed in 2001, founded by the University Library "Svetozar Markovic", Serbian National Library, Library of the Serbian Academy of Sciences and Arts, University Library "Nikola Tesla" from Nis, University Library in Kragujevac and Serbian Academic Library Association. KoBSON has always been funded by the Ministry of Science, providing licenses for access to foreign electronic resources through the Academic Network AMRES. Today, KoBSON provides access to over 35,000 foreign electronic journals for all libraries and institutions connected to the Academic network.
The Old and rare book collection contains manuscripts, old and rare printed books, old magazines and newspapers, archival collection and a collection of maps. This collection contains about 13,500 publications that are priceless.
Collection of Cyrillic manuscript books is particularly important. Together with partials it contains 90 items. The oldest manuscripts are from the 13th century. The manuscripts were microfilmed, and digitization is in progress. Collection of manuscripts in oriental languages, written mostly in our region, is highly important. It contains a total of 397 items in 633 volumes. The oldest manuscript dates from year 1206. This collection is completely digitized and included in the Europeana Libraries portal.The collection holds 15 rare incunabula, the oldest printed books of the 15th century, 13 foreign and two Serbian. The rarity collection also holds 220 books from the 16th century, where particularly significant is a collection of books from the 16th century (Srbulje) printed in Venice, Gračanica, Sebeš, Mileševo, Mrkšina church, Skadar, Trgovište and Belgrade. Well-preserved copy of the Four Gospels printed in Belgrade in 1552 is also kept within this collection, as well as 362 books from 17th century and 890 books from 18th century.
Valuable archive collection contains letters and documents spanning from the late 17th to 20 century. The largest part of the collection is personal correspondence of famous people with 4,000 units, and collection of geographical maps and atlases. The most interesting old maps are the etchings with Belgrade plans from 18th century.
In 1987 Assembly of Belgrade University made a decision on the establishment of an information system of the University, where the University Library was determined to be a center for scientific and technical information. In the same year the first terminal connection via modem was established with foreign information resources. Information specialists, experts in various scientific fields, helped users learn how to search specialized databases on compact disks and other electronic publications from the Library. The first database acquired on CD-ROM was the Science Citation Index for the period from 1980. Since 1996 when the project of integration of local area networks in the library and connecting them to academic LOTEX segment of the public network was established, the Internet classroom started offering to users the search of all publicly available information on the Internet and librarians provided help in the search.Today, libraries are no longer just a physical space, but also a hub in the global network, and the collections do not narrow down to the materials in storage, but broaden to all that is available over the Internet. The library currently holds over 1.5 million library items, about 230,000 records in an electronic catalog and access to 35,000 international scientific electronic journals, 40,000 electronic books and around twenty databases, so it is able to meet the needs of researchers.