The present study investigated whether social support mediated the relationship between personality traits and health among African Americans over a 5-year period, filling a gap in the literature on longitudinal tests of the personality-health association. Data were collected from a national probability sample of African American adults (N = 200). Personality was assessed at Time 1 (T1), social support was assessed 2.5 years later (T2), and physical functioning was examined 5 years (T3) after T1. Telephone surveys included measures of the five-factor model personality traits (T1), social support (T2), and physical functioning (T3). Results suggested that relationships between the T1 personality traits and T3 physical functioning were not mediated by T2 social support. Secondary analyses found that among all T1 personality traits, higher openness and lower neuroticism uniquely predicted higher T2 social support. Furthermore, among T1 personality traits, higher conscientiousness uniquely predicted better T3 physical functioning. This information may be useful to health care providers and community members in developing prevention and intervention strategies for African Americans.