This study provides the first comprehensive discussion of conservation in Nazi Germany. Looking at Germany in an international context, it analyses the roots of conservation in the late nineteenth century, the gradual adaptation of racist and nationalist thinking among conservationists in the 1920s and their indifference to the Weimar Republic. It describes how the German conservation movement came to cooperate with the Nazi regime and discusses the ideological and institutional lines between the conservation movement and the Nazis. Uekoetter further examines how the conservation movement struggled to do away with a troublesome past after World War II, making the environmentalists one of the last groups in German society to face up to its Nazi burden. It is a story of ideological convergence, of tactical alliances, of careerism, of implication in crimes against humanity, and of deceit and denial after 1945. It is also a story that offers valuable lessons for today's environmental movement.