Focusing on the emergence and evolution of environmentalism in South Korea and Taiwan since the mid-1980s, this paper analyzes the relationship between democratic consolidation and environmental politics. In both countries, an environmental movement arose after a series of environmental disasters and expanded through the effective politicization of environmental issues by the opposition parties. The general relationship between environmental groups and political parties differs significantly in the two countries compared. In South Korea, environmental groups have maintained relative autonomy from political society, forging only tactical alignments with opposition parties. In Taiwan, the environmental movement from its inception has been closely affiliated with and depended upon the dissident movement. Additionally, in terms of the relationship between the environmental movement and the state, South Korea represents a pattern of "congruent engagement" whereas Taiwan stands for a "conflictual engagement." These differences in the development of environmentalism are closely related to the different modes of democratic transition in the two countries. In South Korea, the intensive "politics of protest" by civil society groups resulted in drastic changes in the ruling bloc. In Taiwan, elite-led and pacted transition largely enabled the ruling regime to maintain its control of society at large. As a result, in South Korea environmentalism emerged as a "new social movement" after the transition, whereas in Taiwan, it served as an essential component of the pro-democracy movement against the KMT government.