The library conveys a ‘universal knowledge’ accumulated over centuries and serves as a repository of Western cultural wisdom. This is particularly true of its historical book collection, which spans a wide range of subjects, including theology, history, art, music, literature, philosophy, and the natural sciences. The collection is also notable for its linguistic diversity and polyglot works.

The non-historical book collection (book publications from 1850 to the present) is dominated by theology. The main areas of focus are church history, patristics, dogmatics and spirituality.

The Beinwil Monastery, founded around 1100, established a library from its very beginnings. In 1648, when the monastery relocated from Beinwil to Mariastein, the library was also transferred. Under Abbot Fintan Kieffer (1606–1677), the library was rebuilt, and his successors continued to expand the collection.

The invasion of French troops in 1798 and the establishment of the Helvetic Republic put an end to the development of the library; it was destroyed as an institution through confiscation and sale.

Under Abbots Hieronymus Brunner (1765–1804) and Placidus Ackermann (in office 1804–1841), the library experienced a new golden age. It was enriched through new acquisitions and antiquarian purchases, including book collections from secularized monasteries.

As a result of the Kulturkampf, the Solothurn cantonal council decided to “reorganize” the Mariastein monastery in 1874; the decision was confirmed by a cantonal referendum on 8 October 1874. The library was transferred to Solothurn in 1875 and became part of the cantonal library and its legal successor, the central library.

The exile of the convent in Delle, in Dürrnberg, in the St. Gallusstift in Bregenz and the takeover of the management of the college in Altdorf, as well as the care of the pilgrimage in Mariastein under state supervision, led to a fragmentation of the convent. ‘New’ libraries were established in all the places where the conventuals were active.

The return of the library holdings to Mariastein began after the legal restoration of the monastery on June 21, 1971. The process of reuniting the collections from Mariastein (Pilgrimage), Bregenz, and Altdorf started in 1981 and is still ongoing, particularly concerning the historical book collection. While the volumes from the Bregenz exile station have been in Mariastein since 1982, the volumes transferred to Solothurn in 1875 have been gradually returned to Mariastein following the restitution agreement signed on March 17, 1998, between the Central Library Foundation of Solothurn and the monastery. This process, too, remains incomplete.