Objective Socioeconomic disadvantage is associated with poorer behavioral and emotional outcomes in children with asthma. This study investigated the associations between maternal income and education and naturalistically observed behaviors and affect during everyday parent–child interactions. Methods 53 predominantly low-income youth with asthma, aged 10–17 years, wore a naturalistic event-sampling device, the Electronically Activated Recorder, for 4 days to assess mother and child positive behaviors and affect in daily life. Results Maternal education, but not income, was positively associated with child positive behaviors, displays of mother and child positive affect, and increased maternal responsiveness. Maternal positive affect and maternal responsiveness mediated the effect of maternal education on child positive affect. Conclusions Our findings suggest that maternal education has an important influence on the socioemotional adjustment of youth with asthma and point to the importance of investigating the independent influence of socioeconomic status components on everyday parent–child interactions.