Why does occupational segregation by gender persist despite decades of progress toward workplace equality? This paper proposes a new mechanism: how the gender typing of jobs influences not only individuals’ beliefs about their competence but also their attitudes toward ambiguity in career-relevant choices. Through three experimental studies, we show that gender-task congruence affects attitudes toward ambiguity, with women displaying higher ambiguity aversion for male-typed tasks in some contexts, and men showing greater aversion toward female-typed tasks in others. This effect is particularly pronounced when gender typing is made salient. Using behavioral measures to separate beliefs from attitudes, we demonstrate that ambiguity aversion toward male-typed tasks significantly predicts the decision to compete in such tasks, beyond the effect of beliefs about performance. Our findings suggest that gender-congruent career choices may reflect not just self-assessments of ability, but also differential comfort with ambiguity across gendered domains. These results have important implications for understanding the persistence of occupational segregation and designing interventions to promote gender diversity in male-dominated fields.