Existing literature repeatedly illuminates the detrimental effects homophobia and heterosexism have on lesbian, gay, and bisexual (LGB) clients and the psychotherapeutic relationship. There is a growing body of literature that discusses the negative effects microaggressions, subtle, often innocuous messages that communicate a denigrating message to an attended target (Constantine, 2007; Pierce, et al., 1978; Sue, et al., 2007b), have on the therapeutic environment. However, research literature fails to discuss the effects subtle forms of discrimination, specifically sexual orientation microaggressions, have on LGB and queer (Q) clients and the therapeutic relationship; nor is there an established typology of microaggressions directed towards LGBQ psychotherapy clients. The dearth of empirical research on sexual orientation microaggressions is problematic given the LGB communitys high utilization of mental health services, and the high probability that sexual minority clients are seen by heterosexual clinicians who most likely, consciously or unconsciously, hold some disparaging views for sexual minorities.The purpose of this study was to utilize a qualitative methodology to explore the phenomenon of sexual orientation microaggressions with 16 self-identified LGBQ psychotherapy clients. It was hypothesized that: (a) themes or a typology would emerge to represent sexual orientation microaggressions, (b) the presence of sexual orientation microaggressions within the individual therapeutic environment would have a negative impact on the therapeutic process, and (c) LGBQ individuals experience sexual orientation microaggressions in a variety of formats within the individual therapeutic environment. Results of this study validated the existence of sexual orientation microaggressions within the therapeutic environment and a typology of eight sexual orientation microaggression themes was constructed. Sexual orientation microaggressions had negative emotive, cognitive, and behavioral consequences for LGBQ clients, and detrimentally impacted the overall therapeutic process. Sexual orientation microaggressions also manifested in a variety of formats, including verbal, nonverbal and environmental transmission. This study extended the empirical research on microaggressions, and implications from this study can be used to advance clinical training and improve the quality of services provided to LGBQ clients.