This article is the first to show that gender shapes the degree to which legislators use formal mechanisms to oversee government activities. Extensive scholarly work has analysed the use of oversight instruments, especially regarding who monitors whom. Whether, how, and why the conformity of men and women with institutional roles differs, has not yet received scholarly attention. We hypothesise that women become more active than men in overseeing the executive when in opposition while reducing their monitoring activities even more strongly than men when in government because of different social roles ascribed to men and women as well as differences in risk aversity between sexes. We analyse panel data for three oversight tools from the German Bundestag between 1949 and 2013 to test this proposition. Our findings imply that characteristics of political actors influence even a strongly institutionalised process as oversight and further clarify the gender bias in political representation.