Extensive buildings were erected, and the church, chapter-room, and dormitory were blessed in 1159, though the entire monastery was not completed until 1218.

Towards the end of the fourteenth century, the abbey was repeatedly plundered, especially in 1426, when 4,000 Hussites sacked and burned it down.

Besides him two other noted historians were members of Zwettl during the nineteenth century: Johann von Frast (d. 1850) and Leopold Janauschek, the author of Originum Cisterciensium.

The modern form of the premises is the result of the Baroque refurbishment in the 18th century, which involved the reconstruction of the principal buildings.

Among other parts the western tower was constructed by Josef Munggenast to plans by Matthias Steinl.

The abbey's library contains over 60,000 volumes, 500 incunabula, and 420 manuscripts, the most famous of which is the Zwettl Stiftungsbuch ("cartulary").