Regular contact with people from another racial or ethnic group can have physiological benefits. The present research explored whether these benefits extend to children who live in families with greater intergroup contact. Specifically, it investigated whether children with asthma had better pulmonary function if their parents reported having more people in their social network who were of a different race or ethnicity, and whether this relationship was moderated by the quality of the relationship between children and their parents. Consistent with hypotheses, results showed that the percentage of people in parents’ social networks who were of a different race or ethnicity predicted better pulmonary function among children who reported higher quality relationships with their parents, but not among children who reported lower quality relationships. Thus, the racial/ethnic diversity of parents’ social networks may play a role in protecting children’s health, particularly when children are close to their parents.