This study examines gender differences in attitudes toward individuals with Bipolar Disorder (BD) at work. Participants (N = 628) randomized to a vignette completed the Attitudes toward Individuals with Bipolar Disorder in the Workplace Scale (social acceptability, competency, reliability, advancement, job demotion/loss). Multivariable regressions found men rated co-workers with BD as more socially acceptable, while women rated co-workers as more competent and less likely to lose their job/be demoted. Mediational analyses assessing whether a personal diagnosis of a mood disorder mediates attitudes toward co-workers with BD and gender found 8–17% of a relationship between gender and attitudes is attributed to a participant diagnosis of depression or BD. These results inform educational/intervention strategies targeting gender-specific attitudes toward individuals with BD. [ABSTRACT FROM AUTHOR]