The Anglo-Saxon origins of Bishopstone church are visible in the long and short quoining of the nave and S porticus, and two windows in the W wall of the nave. A scratch dial set over the S doorway is also thought to be Anglo-Saxon. It is inscribed: +EADRIC.

In the 12thc. the porticus was converted into a porch by punching a doorway through the S wall, and a doorless W tower was added. Around the same time the Anglo-Saxon nave was extended eastwards, providing a chancel of the same dimensions as the nave. The N aisle, on the evidence of its arcade, seems to date from c.1200, but there are four small Norman-style windows in its N wall. The aisle has a catslide roof and continues E, alongside the chancel. The chancel arch is Early English, of c.1200. The single-bay presbytery at the E end of the chancel has waterleaf capitals and probably dates from c.1175. Although a vault was intended from the outset, the present rib vault dates from 1849. Further restorations were carried out in 1885.

In 1086 Bishopstone was, as its name implies, held by the Bishop of Chichester. No church is mentioned. In 1848 the grave slab in the W tower was discovered in the N wall, where it had served as lintel of a fireplace built into one of the pews.

The sanctuary arch (remodelled from impost upwards) dates from the same campaign as the arcading of the chancel.