America has continued to be increasingly diverse in culture and ethnicities. As such, these diverse populations require those in health and mental health fields to adjust to the cultural differences that arise. Central to these conversations is the impact of the acculturation process on immigrant populations. Researchers posit the stress of immigration and the acculturation process leads to increased rates of mental illness (Lang, Munoz, Bernal and Sorenson 1982; Masten, Penland and Nayani 1994; Neff and Hoppe 1993). Assuming that the acculturation process impacts first generation immigrants most, this study investigated U.S. born Blacks with and without Caribbean descent and Caribbean born Blacks residing in the U.S. to determine if nativity status and generational status impacts rates of mental illness. Using the National Survey of American Life (NSAL) dataset which is one of three research projects conducted from 2001 to 2003 by the Program for Research on Black Americans (PBRA), as part of the Research Center for Group Dynamics project, analyses were conducted to determine if relationships existed for these groups. Results indicated that mental illness is dependent on country of origin and U.S. born Blacks do self-report mental illnesses significantly more than Caribbean Blacks. Caribbean Blacks who are first generation in the U.S. are significantly less likely to report mental illness than second generation Caribbean Blacks. Differences in gender, work, number of years living in the U.S., age at immigration and wealth and poverty indicators all show some relationships with mental illnesses. / Ph. D.