Parent and friend support, family stress, and economic hardship are examined as mediators of well-being for 782 African-American, European-American, and Hispanic-American 4th and 6th graders from middle and low income schools. Of these, 172 were immigrants. Well-being indices included loneliness, self-concept, depression, and teacher-rated happiness. Ethnicity and income, but not immigration, effects were mostly eliminated when support, stress, and hardship were included as predictors in regression analyses, consistent with a mediational model. Associations to well-being were positive for parent and peer support and negative for stress and hardship, although some effects varied by grade, ethnicity, or school economic level. The importance of considering children's well-being within the context of a broader social ecology was affirmed. (Author/MKA)