We examine the gender gap in turnout in Switzerland by analysing the 2003 federal elections. Despite being a standard component in electoral studies, the gender variable is, in most cases, only used as a control variable and its effects and interaction are too often under-analysed. We focus on individual-level factors by looking at three types of explanations for the gender gap: (1) resources, (2) political motivations and attitudes, and (3) social capital and integration. Our analysis, based on binomial logistic regression models, shows that compositional and conditional effects play an important role in explaining the persistent gender gap in Swiss electoral turnout.