The west wall is gone entirely, marked only by a few protruding bond stones at the corner, which gives the roofless shell an oddly open quality, as though the building never quite made up its mind to fall down.

A parish church existed at Stradbally by 1302, and by 1398 one Thomas, son of John de Geraldinis, held the rectory of what was then recorded as 'Stradbalybog'. The present fabric dates from the late fifteenth or early sixteenth century, and was still considered in repair as recently as 1615, though by 1756 the antiquarian Charles Smith was already recording it as a ruin. What survives, measuring roughly 15.7 metres by 5.67 metres internally, is built of coursed rubble with ashlar quoins and dressings, the fine-cut stonework used at corners and around openings that distinguishes a building of some ambition. The east gable is particularly well preserved, retaining its ashlar coping and a two-light cusped ogee-headed window, the graceful pointed-arch form fashionable in late medieval Irish church building, though its central mullion is now missing. The pivot hole and draw-bar sockets for double wooden shutters survive in the stonework. Elsewhere, the south wall still carries an aumbrey, a small wall cupboard used to store liturgical vessels, and beside it a piscina, the shallow stone basin with a drain where a priest would rinse his hands and sacred vessels during Mass. Its circular basin is fluted radially and retains its central drain. A reused sandstone sill carved into one of the window jambs hints that an even earlier structure stood on this site before the present building was raised. Seven water spouts from the original roof drainage system also survive, six along the south wall and one at the east end of the north wall, with a fallen spout lying outside the south door.

The interior is crowded with overground tomb monuments, which make the floor difficult to read, but the walls themselves reward close attention. The grooves cut into window jambs for glass, the shallow carved basin tucked into a window embrasure, and the beam holes that may once have supported a gallery or loft at the west end all suggest a building used carefully and adapted over time, long before the roof finally gave way.