Background Prior studies observed involvement with video games to vary between different sociodemographic strata with considerable higher gaming time in males compared to females. However, empirical evidence explaining the gender gap in gaming time is still scarce. The present study aims to evaluate if the higher gaming time can be attributed to gender specific game genre preferences. Methods A nationwide representative survey comprising 3073 participants aged 16-93 years (M = 49.1; SD = 18.2) was conducted. Video game use and genre preferences were assessed via a written questionnaire. OLS regression and subsequent mediation analyses were used to determine significant predictors of gaming time and to evaluate the contribution of genre preferences. Results Higher age, high education and employment predicted lower gaming time whereas male gender and the preference of certain game genres predicted higher gaming time. Mediation analyses revealed that the higher gaming time of males is fully mediated by the higher preference of role-playing and shooter games among this gender group. Conclusion The higher gaming time of men is fully accounted for by the male specific preference for certain game genres. Future research should address the functional connection between genre preferences and gaming behavior in further detail.