The rise and fall of Zander-Institutes around 1900 in The Netherlands. Around 1860 the Swedish physician dr. Jonas Gustav V. Zander (1835-1920) set himself to devise different sorts of contraptions. He believed that people who needed medical gymnastics could be treated better and more efficiently with the help of machines. His mechanistic approach can be understood in the context of the upcoming industrialisation that rapidly got a hold on Europe in this period. After a very successful presentation at the World Exhibitions in Philadelphia (1876) and in Paris (1878), the Zander-method soon caught on in the medical world and many so-called Zander-Institutes (which are very similar to the fitness-centres these days) emerged in the bigger cities of various European countries. In the nineties of the nineteenth century Zander-therapy became very popular in The Netherlands as well. In 1894 the first Zander-Institute opened its doors in Groningen. Within four years another eight Zander-Institutes would follow in the major cities throughout the nation. In these institutes physical education teachers, who engaged themselves in medical gymnastics, and physicians worked closely together. This was considered to be a good development, since the domain of medical gymnastics was a heavily contested area in the field of labour in the last quarter of the nineteenth century. After a short flourishing period almost all of the Zander-Institutes had great difficulty to survive in the first decade of the twentieth century. Both rise and fall of the Zander-Institutes can be ascribed to a combination of factors of a scientific (with regard to the method), social (viz. legislation concerning the care of the crippled) and professional (with regard to the different strategies of the involved professions) nature. In this article these factors and the relations between them will be described.