The workplace experiences of lesbian, gay, and bisexual (LGB) workers are underresearched, and this is especially true for bisexuals, who constitute the largest proportion of the sexual minority community. Using stigmatization theory and the minority stress model, we investigated the experience of workplace bullying and associated posttraumatic stress disorder (PTSD) for bisexual workers compared with monosexual workers (gay men and lesbians and heterosexuals) workers. We collected online data of two samples of adult U.S. workers, one LGB (N = 422) and one heterosexual (N = 418). Our measure of workplace bullying included two subscales: person-related (bullying directed at the individual person) and work-related (bullying related to accomplishment of work goals). First, we found bisexual workers reported higher person-related bullying than gay men and lesbians, but not heterosexuals; they did not differ from monosexuals (gay men and lesbians and heterosexuals) in work-related bullying. Second, bisexuals were significantly higher than both groups of monosexuals in PTSD. Third, workplace bullying moderated the relationship of sexual orientation and PTSD, showing that bisexual workers who reported frequent bullying were disproportionately higher in PTSD than monosexual workers. Our findings show that bisexuals experience work-related events differently than do other groups and additional research should continue to explore this LGB subgroup. Further, this study confirms that work-related PTSD is worthy of further investigation among sexual minority workers and specifically bisexuals. Public Significance StatementOur findings suggest that more needs to be done to discover nuances that affect relationships among workplace bullying and PTSD, particularly for potentially disadvantaged groups in the workplace. Of note is the importance of disaggregating the work experiences for different subgroups within the sexual minority community. Our study demonstrates not only the prevalence of workplace bullying against bisexuals but the costs to individuals and organizations for ignoring their experiences. Since ample research reveals that organizational policies and leadership support can minimize workplace bullying and maximize workplace civility, management attitudes and practice do matter in establishing and maintaining a working environment that is welcoming to all.