Negative and often unconscious beliefs about marginalised groups, including women and people of colour, sometimes manifest in discriminatory and degrading slights called microaggressions. Since most often microaggressions are in the form of subtle actions, unobtrusive comments, or humorous gestures, they are frequently overlooked as innocent and harmless, specifically to bystanders. However, their adverse effects on those on the receiving end are anything but innocuous, even if perpetrators are utterly unaware of their harmful comments or behaviours. Minorities and marginalized individuals often find microaggressions more harmful than blatant racism and discrimination. Six hundred and eleven STEM (Science, Technology, Engineering, Math) faculty from ten USA universities completed an online survey in the spring of 2021, of which 39% self-identified as Underrepresented Minority, URM, faculty. This study revealed that on average, URM women were 50% more susceptible to gender microaggressions, which correlated negatively with autonomy (having choice) and competence (being capable and effective), and positively with amotivation (lack of motivation). Case in point, 38% of them believed their opinions were overlooked in a group discussion because of their gender. Women with intersecting identities, such as women of colour, experienced both forms of gender and racial/ethnic microaggressions. They have experienced being ignored at work, being treated differently, and their opinion being overlooked based on their gender and/or their race/ethnicity. While detecting bias and microaggression and acknowledging their occurrence is crucial, taking deliberate and precise actions to disrupt and prevent them from re-occurring is even more pivotal. By realising the prevalence of discrimination and microaggressions towards underrepresented minority female faculty, and sharing insights into the complex and overarching race, ethnic, and gender relations among other social constructs, this study deepens our understanding of the challenges and barriers that this group has to grapple with. By adopting and creating effective institutional policies and professional training in support of diversity, inclusion, and cultural competency we can improve the experiences of URM faculty and positively impact their motivation and productivity.