A simple three-cell building of nave, chancel and semicircular apse without tower or belfry. There is a chancel arch and the remains of an apse arch. Construction is of herringbone and rubble masonry with brick repairs. The nave has been heightened, and the upper levels are of small, uneven ashlar blocks. Brick buttresses have been added to the N side of the nave, and a large brick doorway on the S must date from its conversion to a barn.

In 1086 Isleham was a demesne vill of the king (6 hides and 40 acres). A further 1½ hides and 20 acres were held by the Bishop of Rochester under Archbishop Lanfranc. Hugh de Port had another holding of the same size, and Count Alan's 40 acres were held under him by Geoffrey. The Priory was founded as a cell of the Benedictine Abbey of St Jacut-de-la-Mer, in Brittany. It was suppressed in 1414 and given by Henry VI to Pembroke College, Cambridge. The new owners demolished the priory buildings except for the church, which they converted into a barn. This was its use until 1944. It is now an English Heritage property.

The chancel arch arrangement with paired half columns and a second-order nook shaft also occurs at Hauxton, although the forms of the cushion capitals differ.