Sexual minorities face stigmatizing experiences which can lead to disparities in physical and mental health, as well as social and economic resources. Additionally, research suggests that microaggressions, or small actions and comments that speak to a person’s prejudices, act as stigmatizing experiences and contribute to negative outcomes for the stigmatized. However, most studies of sexual minority health do not explore bisexual experiences uniquely, despite evidence that bisexuals have unique experiences of stigma and microaggressions. Those studies that do explore bisexual experiences find worse outcomes for bisexuals than their lesbian or gay counterparts. Thus, the current study developed a quantitative scale for assessing experiences of microaggressions specific to bisexuals. A 35-item scale formulated around previously identified microaggression types was validated using data from a sample of 232 bisexuals. Results indicated that bisexual microaggressions were distinct from homonegative microaggressions and that bisexual microaggressions were related to worse physical, psychological, and environmental quality of life. This scale is an additional tool that researchers may use in understanding how stigma experiences lead to negative outcomes, as well as to identify opportunities for alleviating disparities.