The construction of the Cistercian monastery, as it is preserved today, began approximately in the year 1163, that is, about ten years after its foundation, following the usual practice. It is documented that in that same year Arnau de Bordells made a donation for the definitive stone construction and that Ramón de Cervera, lord of Espluga Jussana, authorized the monks to extract the stone necessary to build the monastery and its outbuildings. The Cistercian buildings paid special attention to the environment and the location, being essential to have a nearby water flow that would allow the extraction of the necessary channels for the complex.

When a Cistercian monastery was founded, provisional rooms were initially erected for community life, awaiting the construction of the large definitive building, which usually began between ten and twenty years later, although in some cases there was already an old and modest building where the monks began their residence. At the beginning of the great stone works, a small chapel was quickly erected, which was later used for functions such as the infirmary and, in the case of Poblet, even had a small cloister, known as the cloister of Saint Stephen or the Infirmary, dedicated to the patron saint of the church; this chapel later became a funerary chapel, constituting together with its cloister the oldest nucleus of the enclosure, dating back to the 12th century.

While the monks resided in this nucleus, the definitive church was built between 1162 and 1196, and in 1200 the north wall adjacent to the cloister was completed. Then, the primitive chapter house was built -which would be transformed years later- the old sacristy, the parlor and the monks' dormitory on the upper floor. During the middle of the 13th century extensions and renovations were made, as evidenced by various documents of donations and wills; between 1225 and 1234 the work on the refectory for converts is mentioned and, in 1243, reference is made to the construction of the dormitory, which suggests that by the middle of that century at least three of the four sides of the cloister were already erected. Donations made in 1249 and 1250 indicate that the funds were destined to the works of the "new chapter" and the ornamentation of the "new sacristy" and the "new dormitory", that is, to replace or remodel the original rooms of the end of the 12th century.

The monastery was enlarged in the 14th century with the construction of Bishop Copons' atrium, the cellar that replaced the lay dormitory and a dormitory for retired monks, and towards the end of the same century the complex known as the palace of King Martin the Humane was built. Finally, between 1789 and 1792 the new sacristy was built, attached to the south wall of the church and occupying part of the line of the wall.