Research has demonstrated a protective effect of social support on health. Social support is most often treated as an independent variable. However, as with disease risk factors, which are not randomly distributed, health-promoting resources such as social support are also systematically patterned. For example, in the USA, family support is thought to be high among Latinos, Mexican Americans in particular. Using data from the Project on Human Development in Chicago Neighborhoods, we explored the relationships between ethnicity/nativity status, socioeconomic status (SES) and perceived social support from family and friends. We also assessed the role of retention of culture-measured as primary language spoken at home-on social support. Finally, we tested whether SES moderated the relationship between ethnicity/nativity status and social support. Foreign and US-born Latinos, most notably, foreign-born Mexicans, reported higher family support compared to non-Latino whites. Primary language spoken at home seems to account for the relationship between ethnicity/nativity and familial social support. Mexican-born and US-born Latino immigrants reported lower social support from family at higher levels of SES. Each ethnic minority group reported lower perception of friend support compared to non-Latino whites. There was a strong SES gradient in subjective support from friends with higher support reported among those with higher SES. This study provides evidence for the notion that Latinos in the USA, specifically foreign-born Mexicans, may rely on family ties for support more than do non-Latino whites. Findings also help identify ethnicity/nativity status, primary language spoken and SES as determinants of social support. Specifically, the higher familial social support found among Latino immigrants may be due to retention of culture. Effect modification by SES suggests that Latinos of lower and higher SES may differ with regard to the traditionally-held value of familism.