We analyze the impact of unemployment on the mental health of Mexican immi - grants, comparing them with Mexicans born in the United States, other Hispanics, and white and African-American natives, using the 1999 and 2009 National Health Interview Surveys . Noteworthy is the low prevalence of mental health disorders among Mexican immigrants. Despite strongly increased unemployment rates, mental health problems remained rather stable; neverthelesswhile accounting for the possibility of bidirectional causality using instrumental variablesour findings suggest a strong negative effect of unemployment on mental health. Group compo - sition effects help to explain this. The impact of unemployment on mental health strongly increased among native whites while for the socioeconomically more disad-vantaged African-Americans and Hispanics the impact was unchanged.