The palatial rooms give an idea of the extravagant lifestyles of the Teutonic Knights. The illustrious architectural history of the castle can be seen at the Renaissance-era Bewart Staircase and the Pillar Hall. The Rococo is represented at the Room of the Gods, and the New Royal Quarter, and Classicism at the Chapter Hall and the main staircase. The jewel of the residence is the church that was built in part by Balthasar Neumann and François de Cuvilliès.
The history of Bad Mergentheim is also interpreted, from its humble beginnings to the current status as a spa town. There is an exhibit of medieval sculptures, wood paintings, exotica, tin-glazed pottery, alabaster and marble reliefs of the Renaissance and Baroque, precious miniature furniture, arts and crafts, and other curiosities that belonged to Freiherr Carl Joseph von Adelsheim. There is also a collection of 40 doll houses and kitchens, as well as shops from the 19th and 20th centuries. The town history wing has a Mörike exhibit that is dedicated to the seven-year stay of the Swabian poet in Mergentheim.
In May 2015, a completely new wing with the title “4,500 Years Ago. Home in the Tauber River Valley” opened. The exhibit was designed, created and financed by the Verein Deutschordensmuseum e.V.