An estimated 4% of men and 9% of women identify as non-monosex, a term for sexual identities outside of the heterosexual/homosexual binary, such as bisexual, pansexual, polysexual, and asexual. In addition to experiences of oppression shared with all sexual minorities, non-monosex-identifying persons face additional issues of monosex bias in their personal lives, in mass media, and in research. Despite social work's commitment to issues of social justice and inclusion, prior reviews of the literature have indicated a gap in research on non-monosex-identifying persons, which can lead to inappropriate clinical practices and continued stigmatization. The authors of this article examined the state of social work literature on non-monosex-identifying persons through a systematic review and content analysis of primary-study data-based publications from 2008 to 2016 in 24 social work journals based in the United States. Only four articles were found that met the inclusion criteria, and while 31% of the 357 total study participants identified as non-monosex, a content analysis showed subtle forms of monosex bias in the reporting of study results, such as collapsing of gay/lesbian participants with non-monosex participants and the use of marginalizing language. Implications and suggestions for future social work researchers are discussed.