The church was constructed in 1914–1915, when Grästorp had recently grown into a market town. Sources differ slightly on the architects involved: one account credits Torben Grut alone with the design, while the Wikipedia entry names three architects, Carl-Wilhelm Gustafsson, Torben Grut and Albin Gustafsson, as jointly responsible.
The building combines a nave and a narrower, straight-ended chancel to the east, with a tower at the west end. A porch is attached to the north side of the nave, and a sacristy adjoins the chancel to the north. The exterior walls are built of brown and red brick laid in a monk bond pattern, left unplastered, giving the long, steep-roofed nave a distinctive rugged character. The roof is covered in slate, while the tower has a copper-clad spire topped with a gilded cross on an orb.
Inside, the decorative painting was carried out by John Hedaeus and G. Hallencreutz, combining touches of medieval, National Romantic and Art Nouveau (Jugend) styles. Painted borders and scrollwork run along the walls and window frames, and the chancel walls carry stencilled decoration. The altarpiece depicts the Ascension of Christ.
A clock was added to the tower, though the two sources disagree on the year: one gives 1947, the other 1949. The church has two organs, a main organ built in 1972 and a smaller chancel organ added in 1984, both by Smedmans Orgelbyggeri.
One published account of the church, from the book Våra kyrkor, describes its character as scarcely shared by any other church in Sweden, partly because relatively few churches were built during this particular period.