The exact date of construction has been debated, with estimates ranging from around 1250 to 1340. Stylistic features, including the polygonal chancel and the tall round-arched blind arcading on the north wall, closely resemble churches in the former East Prussia region, suggesting the later end of that range, possibly the 1340s. The church was likely commissioned by a lord of nearby Salsta manor rather than, as once suggested, an archbishop; historians now consider Nils Abjörnsson, a powerful knight and royal councillor, the most probable patron.
Unusually for the region, Tensta never had a tower. Instead it had a slender medieval timber ridge turret, remnants of which can still be seen in the roof space; this was demolished in 1810. A large church bell cast on site in 1512 by the bellfounder Busse Jacobsson proved too heavy for the turret and instead required its own free-standing wooden bell tower, built in 1756, which still stands on a hill east of the church.
The interior is dominated by wall and vault paintings completed in 1437 by the artist Johannes Rosenrod, commissioned by the knight Bengt Jönsson Oxenstierna, whose family held the patronage of the church through their ownership of Salsta manor. One image, showing Bengt Jönsson kneeling before the apostle Peter, is considered the earliest deliberate portrait in Swedish art history. Further paintings were added by other, partly unidentified, masters into the early sixteenth century, including a sequence illustrating the life of Saint Birgitta. The paintings were later limewashed over and rediscovered and restored from 1894 onwards, with further conservation work carried out in 2014.
Among the furnishings is an oak altarpiece probably made in a north German workshop in the late fifteenth century, tentatively associated with the studio of the sculptor Bernt Notke. The church contains two font basins, one from the 1200s and a later one from the 1400s, and a mid-eighteenth-century pulpit decorated with a sunburst motif enclosing the Hebrew name of God. Nearby, an early Iron Age burial field and several Viking Age rune stones point to the long-standing significance of this site well before the church itself was built.