The Erfurt University Library has integrated the following libraries - as envisaged in the founding concept of the University of Erfurt:
Library of the former Kirchliche Hochschule Naumburg The former Kirchliche Hochschule Naumburg was closed in 1993. In 1995, the University of Erfurt received the literature stock (approx. 142,000 volumes) of this college as a permanent loan (Depositum Naumburg). This collection was integrated into the university library and is listed on the online catalog.
Library of the former Pedagogical College Erfurt/Mühlhausen In the course of the integration of the Pedagogical College Erfurt/Mühlhausen, an agreement on cooperation in library matters was concluded in 1997, which also regulated the integration of the literature holdings of the Pedagogical College (approx. 300,000 volumes). As early as January 1, 2000, the library of the Pedagogical College was integrated into the University Library; the holdings are listed on the online catalog.
Library of the Faculty of Theology of the University of Erfurt (TFE) With the conclusion of the state treaty between the Free State of Thuringia and the Holy See for the integration of the Faculty of Theology into the University of Erfurt, the University Library took over the seminary library of the Priesterseminar GbR (121,000 volumes). These holdings are indexed on the online catalog and are available in the university library.
Furthermore, the library was able to acquire several outstanding private collections, either in whole or in part, through purchase or as gifts or bequests: