The plan of the abbey church is a reduced version of the usual Cistercian scheme. There is an aisled nave, although the arcades are not symmetrical and there is some doubt as to whether the N aisle was ever completed. Each transept has only one chapel and there is a two-bay, rib-vaulted chancel.

The S transept chapel is barrel vaulted with a plain round-headed E window.

The quality of the carving in the E end of the church is good, but it dimishes westwards. The church was shortened during the later Middle Ages by the insertion of a wall that was surmounted by a tower. The upper walls were also remodelled during this period. The buildings of the E range and some ruinous structures in the outer precincts, including the gatehouse, remain.

Corcumroe was colonised from Inishlounaght in 1194/5. The founder was either Domnall Mór Ua Briain, King of Thomand or his son Donnchad Cairprech. A community had certainly been established there by 1198 when monks were sent from Corcomroe to colonise a new abbey at Kilshane in Limerick.

Following disciplinary measures taken against the mother house of Inishlounaght, Corcumroe's affiliation was transferred to Furness Abbey. In 1271 affiliation was transferred once more, this time to Mellifont. In 1417 it was recorded that the abbey was so poor that the monks could not be properly maintained. In 1554 the abbey was granted to Murcadh Ua Briain Earl of Thomond, and in 1564 to Domhnall mac Conchobair Ua Briain. It continued to function to a limited extent following the dissolution, with John O'Dea, a monk of Salamanca, appointed as abbot in 1628.

Although monks were certainly established at Corcomroe by the late 12thc., the earliest parts of the present building are unlikely to date much before c.1210 to 1225. Stalley (1975) has highlighted the manner in which the quality of the sculpture becomes quite dramatically poorer during the construction of the presbytery, suggesting the downsizing of an ambitious scheme as it progressed from N to S. Certainly by the time the remainder of the church was constructed, devoid of sculpture, it is evident that the monks must have fallen on hard times. This may be explained by a record of famine and unrest in Connaught, recorded in the year 1228, and also by unrest within the Cistercian community brought about by the conspiracy of Mellifont.

Stylistically many parallels can be drawn between Corcomroe and buildings attributed to the so-called School of the West. The curious biting beasts on the external angles of the presbytery are very close in form to those carved at the base of one of the reset jambs of the Romanesque doorway at Killaloe cathedral. The herringbone chevron of the Corcomroe vault is paralleled in the E window at Killaloe. The base mouldings of the eastern parts of the church are matched at Boyle ( Roscommon), Abbeyknockmoy (Galway), O'Heyne's church, Kilmacduagh (Galway) and Kilfenora (Clare). One element of Corcomroe's sculpture that sets it apart from the School however, are the naturalistic botanical carvings found on a number of the presbytery capitals and corbels. A number of these have been identified as plants which would have been common to a medieval monastic garden, and there is the suggestion of a precocious sculptor taking inspiration from the plants around him (Stalley and Nelson, 1989).