Over time and across countries, researchers have noted frequent and mostly unexplained gender differences in the levels of support for policies of free or freer trade: women tend to be less favorable toward policies of liberalizing trade than men. Yet, no well substantiated theoretical or empirical account of the gender component of trade attitudes has emerged. Using an economic security explanation based principally on a mobile factors approach, we find that it is not women generally who are more negative toward trade but particularly economically vulnerable women – i.e. women from the scarce labor factor. We utilize recent survey data on individuals’ attitudes toward different facets of trade and its effects across three disparate regions to examine this phenomenon empirically. An economic security approach helps to explain the marked differences in attitudes toward trade among lower- and higher-skilled females in developing and developed countries.