The library's holdings may be classified as follows: A collection of antique books within the Cultural/Historic Department (about 15,000 items from the 16th to the first half of the 20th c.), and a specialized reference library associated with each of the Museum's six departments.

It has been envisaged to turn a part of the "Stari grad"'s Gothic tower into new library premises. The holdings will thus be given a more appropriate location and become accessible to a variety of experts from different areas (history, art, literature, civil engineering, natural sciences...).