Previous studies have found that left-wing and libertarian individuals are more likely to engage in extra-institutional political activism. However, due to a lack of suitable data, studies to date have not analysed the relative influence of economic redistributive and social libertarian values for the intensity of protest participation. By analysing data from a unique cross-national dataset on participants in mass demonstrations in seven countries, this article addresses this gap in the literature and provides evidence of the relative impact of economic redistributive and social libertarian values in explaining different degrees of protest participation. We show that there are divergent logics underpinning the effect of the two value sets on extra-institutional participation. While both economically redistributive and libertarian social values support extra-institutional participation, economically redistributive protesters are mobilized to political action mainly through organizations, whereas the extra-institutional participation of social libertarian protesters is underpinned by their dissatisfaction with the workings of democracy.