The church's origins lie in the 13th century, when it was probably built in Romanesque style with a narrower chancel than the nave. Much of the present nave survives from this earliest phase, and the sacristy may also be early. During the 14th or 15th century the building was extended eastward, and towards the end of the 1400s the present chancel with its three-sided east end was constructed. At the same time the nave walls were raised in brick and decorated with blind-arch friezes, an unusual embellishment for a rural parish church, and the west gable was raised using timber boarding, a rare technique.
The exterior walls combine split granite blocks with brick in the upper sections, gables and chancel, all rendered and painted yellow. The medieval south doorway, with its broad plank door and old iron fittings, remains the main entrance, while a blocked west portal also survives from the Middle Ages. Inside, star vaults cover the nave and ribbed vaults the chancel, both limewashed along with the walls. No medieval wall paintings have been found, though traces of a Renaissance-period painting survive near the pulpit, along with a later drapery painting. A closed-in pew arrangement from the 1600s also remains.
By 1868 the church had fallen out of use as a place of worship and stood empty for several decades; most of its furnishings were sold off at this time. It was extensively renovated between 1924 and 1925 under architect Sven Brandel and reinstated for services, with new fittings acquired for the reopening. A further restoration in 1955–56, led by architect Harald Thafvelin, uncovered and marked older windows and doorways in the plasterwork and gave the church its current yellow colouring.
Among the furnishings, the plain sandstone font in the chancel dates from the church's earliest period, though its base was remade in 1951; during the years the church stood abandoned, the font bowl reportedly served as a flowerpot on a local farm. The pulpit, early 19th century and painted pale grey with gilded ornament, originally stood in Helga Trefaldighets kyrka in Uppsala before being acquired for Fittja in 1925; an earlier pulpit donated to the church in 1688 was sold on in 1895. A freestanding bell tower stands some way from the church; the original, built in 1767–68, was destroyed by a lightning strike in 1997, and a replacement was erected nearer the church in the following years.