The “Catalogue of Manuscripts in the IRCICA Library” prepared by IRCICA’s experts in Manuscript Studies and Bibliographies resulted from an extensive and elaborate research project. It contains much larger information than descriptions of the contents and features of the manuscript works preserved in the library of IRCICA, since each work has additionally been studied for its author(s), provenance, importance in its historical, cultural and scientific context, subsequent references, copies and studies about it. The collection amounts to 530 works in 284 volumes. The Introduction prepared by the authors not only records consolidated statistics on the collection according to subject areas, languages, etc. but offers instructive reading on the contents of several major works of history and culture belonging to eminent authors, many rare works and works of special value, and cases of particular subjects relevant in manuscript studies. The catalogue facilitates researchers’ awareness of the valuable manuscript sources available at IRCICA. At the same time, it is a contribution to source studies and manuscript studies in the fields of Islamic history and civilization.