Ethnic microaggressions are a form of everyday, interpersonal discrimination that are ambiguous and difficult to recognize as discrimination. This study examined the frequency and impact of microaggressions among Latino (n = 247) and Asian American (n = 113) adolescents (M[subscript age] = 17.18, SD = 0.75; 57% girls). Latino adolescents reported more frequent microaggressions that dismiss their realities of discrimination and microaggressions characterized by treatment as a second class citizen than Asian Americans, but similar levels of microaggressions that highlight differences or foreignness. There were no ethnic differences in the extent to which adolescents were bothered by microaggressions. Moreover, even supposedly innocuous forms of discrimination are associated with elevated levels of anxiety, anger, and stress, which may increase feelings of depression and sickness. Microaggressions should be recognized as subtle discrimination that send messages about group status and devaluation, and similar to overt discrimination, can evoke powerful emotional reactions and may affect mental health.