In 1887 the children's spa rooms were opened. In 1912 Prof. Dr. Oskar Vulpius opened a sanatorium containing 120 beds to treat bone, joint and gland sufferings. Meanwhile, a new brine bath was built and opened in 1903. In 1921 there were around 84,500 overnight stays. The recognition of being a spa town goes back to a decree of 1930 by the ministry of Baden. Since then the municipality took the name "Bad Rappenau". After World War II cure bustle increased heavily. In 1952 it has been the seventh biggest spa town in Baden. In the 1970s there were four special clinics consisting around 600,000 overnight stays.