AbstractThis article is about Martin Luther's economic ethics. Background information is given about the economic situation 500 years ago. The high levels of poverty in Germany were the main reason behind the health crisis experienced at that time. Luther reprimanded the heads of families to work diligently and honestly in order to ensure a stable income for the family. He prophetically also criticised the dishonesty on the market place. He exposed the many attempts by people to exploit the poor. An overview is given of the development of his economic thought. The focus falls, however, on his essay Von Kaufshandlung und Wucher (1524) [On trade and profiteering].