Previous research has shown that parent mental health is associated with asthma morbidity in children. However, the biological pathways explaining these relationships are not known. The present study tested whether parent psychological characteristics could predict longitudinal changes in inflammatory markers in children with asthma and a comparison group of healthy children. For this, 33 healthy children (17 m/16 f; 13.5 years) and 50 children with asthma (37 m/13 f; 13.3 years) were assessed at two time points on average 208 days apart. Parent depression (CES-D) and perceived stress (PSS) were assessed at baseline, child depression (CDI) and anxiety (RCMAS) at follow-up. Asthma-relevant inflammatory markers eosinophil cationic protein (ECP) and stimulated interleukin-4 (IL-4) production were measured at baseline and at follow-up. Hierarchical regression analyses controlling for asthma severity and medication use revealed that higher levels of parental perceived stress at baseline were associated with greater increases over time in children's IL-4 production (beta=.29, p=.019) as well as ECP release (beta=.27, p=.004). Additionally, higher levels of parental depression at baseline were associated with increases in ECP over time (beta=.19, p=.046). There was no evidence that these associations were mediated by child depression or anxiety. These results demonstrate that parental stress and depression at baseline predict increases in children's inflammatory profiles over a six month period. This pattern appeared in both children with asthma and healthy children, and was not due to effects on child psychological states. These changes in inflammatory makers may represent one biological mechanism underlying the association between parental distress and child asthma morbidity.