Archbishop Bulkeley's Visitation of that year recorded, with some exasperation, that the parishioners of Westpalstown were 'all recusants saving one man called Thomas Millinton,' meaning they had refused to conform to the established church and were instead attending Mass at the house of the Lady Dowager of Howth, served by a priest named Roger Begg. The sole Protestant in the parish, Thomas Millinton, stands out as an oddly solitary figure in the historical record, a congregation of one in a roofless church.

The building itself had been in trouble for some time before that. By 1615, the Royal Visitation of Dublin, recording churches in the Deanery of Garristown, noted that the curate Nicholas Bacon was serving Westpalstown but that the chancel was already in ruin. The 1630 visitation added that the curate William Tedder was earning a meagre thirty or forty shillings a year for his trouble, and that the church and chancel were both down. What survives today are the lower courses of a plain rectangular building, running roughly 17.4 metres east to west and 6 metres north to south, of randomly coursed masonry rising to less than a metre in height in places. Dressed quoins, the cut corner stones used to give a building structural integrity and a tidier finish, are visible at the nave end. The west doorway retains its round arch and chamfered jambs, and a plain recess in the south wall is thought to be the remains of a piscina, a small stone basin used in medieval liturgical practice for rinsing communion vessels. The church appears in the 1654 to 1656 Civil Survey of Dublin simply as 'the walls of ye parish church,' which tells its own story.

The ruins sit in the northern quadrant of a rectangular graveyard enclosed by hedgerow, set back from the Ballyboughal road in a field. By 1887 a visiting observer found the remains so overgrown with ivy and so reduced that he declared it would be very difficult to say what the original style and shape of the church had ever been. The walls are currently uncapped and have been pointed with concrete, which conservationists note may be trapping moisture and causing internal decay over time. There is a single narrow slit window with a widely splayed embrasure in the south wall, worth looking for as one of the few surviving openings in decent condition.