The West German Green Party's 1983 entrance into the Bundestag marked a major break, both in the history of this young political force and the parliamentary system of the Bonn Republic. The Greens had been founded in opposition to the guiding principles of the West German postwar consensus and conceived of themselves as an “anti-parliamentary party.” Although they had gained parliamentary experience in some regional chambers, their entrance onto the national parliamentary stage juxtaposed old ideals and new challenges—for the Greens themselves as well as for German political culture. Taking this singular historic moment as a starting point, this article summarizes the formation of the Greens in the context of the changing political and ideological landscape of the 1970s. It also contrasts the party's formation with the transformations in terms of program and personnel that it undertook during the 1980s. The focus lies less on the specific activities of the green parliamentary group than on the broader developments in green politics and thinking.