The Renaissance tower was built in 1582-91 using large red medieval-style bricks. At the top of the lower stage, projecting blind arcades on corbels, a common feature on Danish Renaissance buildings. Triangular pediments above the window-openings. The original spire was pyramidical  but it collapsed in 1628. It was replaced by a new spire, but that was lost in the great fire of 1795 which destroyed the whole church except the brick tower. Thereafter the tower had no spire until 1909 when the present copper-clad spire was built, paid for by the brewer Carl Jacobsen. It is in the style of the earlier 17th century spire.

Over the portal in the tower a statue of St. Nicholas. The tower has large sloping buttresses. Following the fire of 1795, the church itself was not re-erected until 1914-17, and then for other purposes such as museum, library, lecture room. It is, however, in the shape of a church of the Renaissance period.