The Diözesanmuseum in St. Pölten is located on the first floor of the former monastery cloister. It was founded in 1888 and was the first such museum in Austria. Under the patronage of the Christian religious art association in Lower Austria, it experienced a rich and varied collecting activity in its beginnings, ranging from archaeological finds on historical documents, coins and medals to objects of painting, sculpture and artcraft from all eras. The focus of the extensive collection is the sacral art, which is presented in all its diversity - from sculptures, paintings, altars, liturgical equipment and clothes. In the early years the museum was housed in the rooms of the former abbey library, meanwhile it has been extended by several rooms.
The following rooms are also integrated into the exhibition space:
• the library of the former Augustinian Monastery with ceiling frescoes by Paul Troger and Daniel Gran
• the "Kerens library", named after the first St. Pölten bishop, with valuable furnishings.