The Maurits Sabbe Library of the Faculty of Theology and Religious Studies (KU Leuven, Belgium) is home to an impressive Jesuitica book collection of almost 100,000 books. 20,000 books printed before 1840 and more than 40,000 from the later 19th and 20th century have been properly described and catalogued. This project aims at disclosing the remaining uncatalogued books, providing easy access to its contents and stimulating academic research in the field of Jesuit studies.