Simple aisleless church with Romanesque nave and chancel, and a late medieval tower. There are two small, plain, round-headed windows in the nave, one on the chancel, and a blocked Romanesque doorway, plain with chamfered imposts, in the N nave wall. The chancel and nave N wall are built of coursed rubble of a local sandstone, with put-log type holes around.On the interior, on the N and S chancel walls, are two round-headed, blind arcades of four bays, supported on plain conical corbels; they are probably 19thc. rather than Romanesque in date, but so heavily whitewashed that one cannot be certain either way. The interior is heavily painted in white throughout. Romanesque sculpture is found on a capital in the fragmentary chancel arch, and on a reset stone in the later SE buttress of the nave. The S wall of the nave, rebuilt in the late 18thc. or early 19thc. when changes were made to the chancel arch, is of grey ashlar.

Originally a chapel of nearby Leek Wootton church, which was held by Kenilworth Priory. Ashow became independent in the time of Bishop Geoffrey Muschamp (1198-1208), but Kenilworth continued to hold the advowson.

A photograph taken before 1958, when the match board ceiling was removed, shows a depressed round-headed chancel arch. According to Clark, this was a 19thc. lath and plaster arch incorporating fragments of a wattle and daub structure 'which had been constructed 400 years previously'.