Emerging evidence suggests that vicarious racial experiences of discrimination may negatively influence child health. Few studies have focus on childhood asthma symptoms and potential moderators of such relationship. Methods We used two population-based cross-sectional studies from the Social Change Allergy and Asthma in Latin America project in Salvador, Brazil. A total of 1003 children and mothers interviewed in 2006 were included, of whom 873 were reached again in 2013. Vicarious racial discriminationwas assessed in mothers by applying the Experiences ofDiscrimination scale. Data on wheeze and environmental exposures were collected with standardized questionnaires. Levels of allergen-specific IgE were measured to identify atopy. Generalized estimating equations were used to estimate the association between maternal discrimination and wheezing and asthma phenotypes. Interaction terms were evaluated to identify whether mothers’ mental health and family social support modified such associations. Results Children whose mothers reported racial discrimination had greater odds of have asthma symptoms (OR 1.75; 95% CI 1.15–2.67) and non-atopic asthma (OR 1.92; 95% CI 1.09–3.40). When we considered effect modification by social support, we found a higher ORs when the level of social support was lower (OR 2.43; 95% IC 1.19–4.97) than when the level of social support was higher (OR 1.12; CI 0.64–1.96). Conclusion Maternal discrimination was associated with asthma symptoms and with non-atopic phenotype among their children. Enjoying wider social support network appears to buffer the effect on asthmatic symptoms. Intervention on childhood asthma needs to incorporate strategies that target the family.