The connotations attached to the concept of 'risk' have changed over the last several decades. In particular, the image of risk, at least in the word's most economically advanced countries, has turned from predominantly positive to highly critical. A sociological look at this historic change reveals the emergence of a plurality of risk definitions that can be attributed to different risk cultures. We can distinguish risk cultures by their proximity to the dominant social practice of risk taking ; namely risk (...) cultures belong either to the centre or the periphery of society. Social movements that resist risky technologies are examples of a peripheral risk culture. Due to a certain concept of social community their perception of risk differs fundamentally from that of the centre. In addition, cultural variation across countries leads to different representations of risk-avoidance in social movements. This contribution illustrates these differences by comparing the American and German anti-nuclear movements. (shrink)