Upper (or Over) Winchendon is 4½ miles W of Aylesbury. The village consists of just the church and a few houses along a minor road in an elevated setting overlooking the Vale of Aylesbury. The church consists of a nave with a N aisle and S porch, chancel and W tower. Nave and chancel are of limestone rubble; the tower is 14thc., of coursed limestone rubble with diagonal buttresses and a S stair, polygonal at the top with a pyramid roof. The bell-openings are of two lights with a mouchette quatrefoil in the head. The plain tower arch, double chamfered and of two orders dying into the jambs, is also 14thc. The nave S doorway, with its heavy angle roll, scalloped capitals and decorated nook-shafts, dates from the mid-12thc. The N aisle of the nave simply consists of three arches pierced through the wall, with wide piers between them. There are no imposts or capitals. This suggests an earlier 12thc.. date for the aisle, and if so the S doorway must be a later addition. The aisle appears to have been widened, and its windows date from the mid to late 14thc. The chancel dates from c. 1200-10, with a pointed and chamfered chancel arch carried on plain jambs, slightly pointed plain lancet windows and similarly plain early-13thc. sedilia and piscina. Below the SW lancet are the remains of a low-side window, now blocked. The pulpit; a 14thc. wooden example with flowing tracery decoration, is by far the earliest in Buckinghamshire and among the oldest in the country. The church was restored in 1877 by William White of Wimpole Street, London. The font is a plain 12thc. tub, and a 12thc. corbel is reset in the chancel S interior wall. The S doorway, font and corbel are described below.

Upper Winchendon was held before the Conquest by the prior and canons of St Frideswide, Oxford, and they continued to hold the manor until the Dissolution. The parish is now part of the Schorne team benefice, i.e. Dunton, Granborough, Hardwick, Hoggeston, North Marston, Oving with Pitchcott, Waddesdon with Over Winchendon and Fleet Marston, and Whitchurch with Creslow.

The chancel arch at Cold Brayfield has features similar to the doorway, including decorated nook-shafts, similar bases and imposts, plain scalloped capitals and a heavy angle roll in the arch.