The present building, consecrated in 1771, is the third church to have stood at Medevi. It is a timber structure finished with white render, built to serve the spa's fashionable visitors as well as the surrounding rural community.
An unusual feature of the interior is that the altar rail and pulpit are built as a single combined structure, and the altar itself faces north rather than the more conventional east. The seating arrangement once reflected social divisions among worshippers: wealthier spa visitors entered through the main southern door and sat facing east, while poorer parishioners and local farming folk entered by an eastern door and sat facing west.
Much of the fixed woodwork, including the altar rail, pulpit and pews, was carved in 1806 by the sculptor Anders Malmström, grandfather of the painter August Malmström. Textiles at the altar were created by the textile artist Ann-Marie Kornerup, adding a later layer to the church's furnishings.
A notable curiosity hangs from the ceiling: a model ship, said to have been donated in 1821 by a disabled resident of Vadstena hospital. Local tradition holds that the ship can forecast the weather, its hemp rigging supposedly responding to humidity, with the direction it swings said to indicate rain, sunshine or changeable cloud for the following day. This is a charming piece of local folklore rather than a verified phenomenon.
Near the entrance stands a wooden relief carved by Anders Malmström in 1789, depicting Jöns Larsson, a coachman at Medevi who also served as "kyrkstöt" (church usher) at nearby Västra Ny church, traditionally tasked with waking sleeping worshippers with a stick. According to local wit, no such usher is needed at Medevi's own chapel, since its steeply raked, straight-backed pews are said to tip anyone who dozes off.