Social isolation is a significant social problem in the United States that many health and welfare organizations have begun to acknowledge and address. Unfortunately, extremely little research focuses on social isolation among ethnic minority populations. This study investigated the association between social isolation from family and friends and the mental health of African Americans and Black Caribbeans. Using data from the National Survey of American Life (2001-2003), we explore 2 indicators of mental health: depressive symptoms (CES-D) and serious psychological distress (Kessler 6). The negative binomial regression analysis examined both objective isolation (infrequent contact) and subjective isolation (lack of emotional closeness) from family and friends. Overall study findings indicated that infrequent contact (objective social isolation) and diminished emotional closeness (subjective social isolation) from family and friends were associated with higher levels of depressive symptoms and serious psychological distress for both African Americans and Black Caribbeans. The addition of subjective social isolation to regression models attenuated the association between objective social isolation and depressive symptoms for both groups. However, the addition of subjective social isolation attenuated the association between serious psychological distress for African Americans but not for Black Caribbeans. These findings contribute to the very limited, but growing body of research on the negative association between social isolation and the mental and physical health of ethnic minorities. (PsycInfo Database Record (c) 2020 APA, all rights reserved).