This article is a case study of the Green Party in Slovakia. The line of explanation of the party’s trajectory is chronological, from foundation to its present marginal status. The two main causes of repeated internal party splits identified by the article are the influence of nationalism and the party’s relationship to the most important formation in Slovak politics during the 1990s, Vladimír Mečiar’s Movement for a Democratic Slovakia. It, furthermore, points to the barrier of a relatively high clause in the electoral system to national parliament which determined the Greens’ tendency to enter wider coalition partnerships. These partnerships, however, had a negative impact on the long-term perspective on the distinctiveness of the Greens from the point of view of voters. Other important factors in the party’s lack of political success have been their isolation from the environmental movement and the public’s low level of interest in ecological and other post-material issues.