The challenges of managing work-family interface have been widely cited as a critical barrier to women’s career advancement. The research examined the impacts of decision-makers’ implicit belief about work-family role relationship on gender bias in evaluating and selecting potential leaders. We propose that people differ in the extent to which they hold a gendered implicit belief about work-family role relationship (i.e., viewing work-family roles as more incompatible for women than for men) and that the stronger the gendered implicit belief the more women employees are disadvantaged in leadership opportunities. By measuring gendered implicit belief in Study 1 and manipulating it in Study 2, we consistently found that participants believing that work and family roles are more incompatible for women than men (i.e., a gendered implicit belief) were more likely to bias against women in evaluations and leader selection, compared with participants with non-gendered beliefs which emphasize either equivalent work-family role conflict or enrichment for men and women. Our research extends the literature on implicit belief to the domain of work-family role relationship, advances research on work-family interface by shifting the attention from experiences of the two roles to the schematic assumption about it, and contributes to the field of workplace bias against women by revealing the impacts of decisionmakers’ gendered implicit belief.