The church consists of a rectangular nave with a straight-ended chancel, its steep gables and rough, unrendered grey stone walls typical of Swedish Gothic building. A timber porch stands before the south-west entrance, and the walls are around 1.5 metres thick. Fire severely damaged the church in 1692, reportedly set by a soldier during wartime; repairs, funded partly by parishioners' labour and gifts, took several years, with the church back in use by 1700.
In 1752 the painter Ditlof Ross of Borås and his assistants decorated the altarpiece and walls, and painted eighteen scenes of Christ with the apostles and evangelists on the gallery front. These paintings survive and are considered the church's finest older feature.
By the early nineteenth century the church had fallen into disrepair, and when the neighbouring parishes built a new joint church at Lena in 1837, Fullestad's church was to be demolished and its materials sold. It was saved when Captain Bauer bought it, reportedly for use as a grain store; the building stood largely empty for decades, with the space under the gallery used as a parish storehouse. Bauer later returned the church to the parish on condition it be properly cared for.
A thorough restoration between 1909 and 1913, led by the architect Torben Grut in a deliberately old-fashioned style, gave the interior its present unified character, blending Renaissance and Baroque elements. Grut chose to retain the old painted gallery rather than replace it, and the restored church was reconsecrated in 1913 after standing unused for some 67 years. A further renovation took place in 1958–59, and a mechanical organ by Grönlunds Orgelbyggeri was installed in 1962.
Outside the chancel lie the remains of the Crusebjörn family and of Baron Carl Hierta of Lagmansholm with his two wives. Beside the towerless church stands a small wooden bell frame, built around 1699, and next to it a stone gateway forming the entrance to the churchyard. The current bell, cast in Jönköping in 1841 and donated by Captain Bauer, carries a devotional inscription encouraging worshippers to hasten to God's house.