The association between leftism and ecologism is analyzed comparatively in a sample of 27 countries, based on data stemming from the fifth wave of World Values Survey (conducted 2005-2007). As a first major result, it is found that the Western countries (encompassing Western European, USA, Canada and Australia) stand out as a distinct group with a highly homogeneous political culture: in the sense that in all of them, ecologism shows a tight “vertical coupling” to the general ideological left-right scale on the one hand and considerable “horizontal couplings” to other leftist issue dimensions on the other. India and South Korea are the only nonwestern countries where a similar (however very moderate) correlation between leftism and ecologism can be found. Secondly, leftist ideologies are most pronounced within highly educated strata in Western countries. Very few other countries (Slovenia, India and Mexico) show a similar pattern. Thirdly, a comparative analysis of age cohorts provides very little evidence for major intergenerational change. In particular, there is no evidence that any interregional or even global diffusion of political ideology has taken place that would cause more transnational homogeneity among younger populations. To summar-ize, we may conclude that “leftist ecologism” is a specific feature of Western countries that unites Western Europe with North America and Oceania, but divides them from South America and Asia as well as from their neighboring countries to the East.