The right to publicly criticize and challenge the government is a fundamental part ofdemocracy. Within the legislative arena political opposition is essential, however, theliterature on oppositional behavior has exclusively focused on general patterns andparty-level variations. Consequently, individual-level oppositional behavior is significantlyunderstudied. Specifically, the absence of a gender perspective is striking. Therefore, thisstudy addresses this gap by examining the relationship between gender and oppositionalbehavior in the Swedish parliament. By combining research on political opposition andresearch on legislative debates, the study develops three hypotheses. Using regressionanalysis, this study tests the general relationship between gender and oppositional behaviorand if the relationship is conditioned by seniority and the proportion of women in partygroups. The study does not find significant gender differences in overall oppositionalbehavior, nor that the general relationship is conditioned by the proportion of women in partygroups. However, the study shows that the effect of gender on oppositional behavior isconditioned by seniority. This finding suggests that women’s tendency to express lessopposition than men, weakness by seniority. This implies that seniority has a positive effecton expressing opposition for female legislators, interestingly, this effect is reversed for menwhere the relationship has a negative relationship with men expressing opposition.