Pettaugh lies on the A1120, midway between Stowmarket and Framlingham, and 9 miles N of the centre of Ipswich. The village clusters around a staggered crossroad on the A1120, but it is not a busy road and the settlement retains its village character. The church stands alongside the main road at the E end of this compact village. The landscape is the typical arable farmland of the East Anglian plain, and a stream runs past the E end of the church, eventually joining the river Deben SE of Debenham.

St Catherine's has a nave, a chancel with a N vestry, and a W tower. The flint nave has a plain c.1300 S doorway under a modern knapped flint and brick porch. The plainc.1300 N doorway is blocked. The windows have cusped Y-tracery,c.1300 in style but all replaced. At the W end on the N side is a flint stair repaired with brick, and on the S wall towards the E end is a piscina set in a rectangular niche, probably 13thc. but described below. The chancel itself is as wide as the nave and the chancel arch is broad and tall; 15thc. in style but probably 19thc. in fact, and extending the full width of the chancel. If the nave piscina served an altar in its present position, therefore, the chancel arch must have been widened. The chancel E window has cusped intersecting tracery, and the S windows and priest's doorway are Perpendicular in style, but all are replacements. Set in the S wall alongside the altar is a crude pillar piscina in a tall, round-headed niche (described below). The chancel and the modern N vestry are mortar rendered: the vestry doubles as an organ chamber. The unbuttressed three-storey 14thc. W tower is of knapped flint with a reticulated W window and a high plinth. The tower arch is tall and plain with a chamfer, and the bell-openings are of brick, except for the E which has 15thc. tracery. The embattled parapet is decorated with flushwork. There was a comprehensive restoration in 1863; the builder was J. Jessop of Helmingham and the architect apparently the vicar. The two piscinas are described below.

The manor of Pettaugh was held by Beorhtweald before the Conquest and consisted of one carucate of ploughland plus 30 acres, and three acres of meadow, and in the same place five free men held 18 acres. There was a church here with 2½ acres of land. In 1086 this was held by Hervey de Bourges. Before the Conquest Thorkil held 20 acres in Pettaugh, with an acre of meadow. In 1086 this was held by Hervey from the Abbot of Ely. Siward held five acres here before the Conquest, held in 1086 by Warenger from the Bishop of Bayeux.

Debenham and Helmingham benefice, i.e. Aspall, Debenham and Kenton and Framsden, Helmingham, Pettaugh and Winston.

Mortlock and Pevsner both label the pillar piscina Norman; neither mentions the nave piscina.