Ruined church, with unaisled nave and chancel and the remains of a Romanesque chancel arch. The building has a complex history. It began as a pre-Romanesque single cell building, probably of 10th–11thc date, to which a chancel was added in the mid-12thc. The building was enlarged in the later middle ages: the nave was extended to the W, the chancel to the E. By 1575 the church was apparently ruinous, but it was renovated during the 17thc. At some point in the late 17th or early 18thc, the building again became derelict and the stone was used as a quarry by local builders. By the 20thc the only part of the building visible to any extent above the ground was the S wall.

During the 1930s many pieces of Romanesque carving from the chancel arch were identified in neighbouring farm buildings, from which they were removed shortly after. The late Harold Leask excavated the base of the chancel arch, finding the lowest stones still in position (1935). The jambs of the arch were then reconstructed, the missing elements being filled in with brick. Further pieces of Romanesque sculpture were discovered in 1977–8, when comprehensive excavation of the church was undertaken by Kildare County Council under the direction of Mr Conleth Manning.

A number of moulded stones from the church are now stored in Kilteel Castle. These include voussoirs from the chancel arch, each decorated with a large roll moulding flanked by fillets; there are two types, one with a roll where the diameter is 0.08 m (2 pieces) and the other where the diameter is 0.06 m (5 pieces). Also stored at the castle is a trapezoidal shaped stone (0.14 m x 0.11 m high), evidently from the side of a gable; decorated with small rolls on each side.

Kilteel provides one of the rare occasions in which Romanesque figure sculpture is found in an architectural context, Ardmore (Waterford) being the other principal example. The existing reconstruction reveals many anomalies and Dr McNab has suggested that the carved stones may have belonged to a doorway rather than a chancel arch. She has suggested that the stones of the doorway were reused in the later middle ages when the chancel was extended to the E. The argument is supported by the fact that no foundations for a 12thc. chancel were found during excavations.

Some of the figure sculpture is well preserved, revealing delicate details, which are remarkable as the carvings were executed in granite. Dr McNab has pointed out similarities with the sculpture at Ely, particularly in the case of the acrobat and the coupling couple. The scene of David/Samson and the Lion also has parallels outside the country. Yet these English influences are incorporated into a programme which shows many distinctively Irish traits: the zoo-anthropomorphic version of St Luke's symbol, for example, or the Fall of Man, the latter following a formulae well established in the earlier high crosses.

The head capitals, with their high cheek bones and interlaced moustaches, belong to a widespread Irish type; it is likely that the same sculptor was employed at Killeshin (Carlow).

The sculpture appears to date from the third quarter of the 12thc.