Background: We examined children's coping and involuntary stress responses as mediators of the relations between parenting or children's effortful control (EC) and adjustment. Method: Two hundred and forty primarily Mexican American 7- to 12-year-old children reported on their EC, coping, involuntary stress responses, and problem behaviors. Teachers reported on children's academic competence. Parents reported on their reactions to children's negative emotions and on children's EC, problem behaviors, and academic competence. Results: There were significant zero-order relations between parents' affective responses to children's negative emotions, children's EC, engagement coping, disengagement coping, involuntary stress responses, and adjustment. Consistent evidence emerged that children's engagement coping and involuntary stress-responses mediate the relations between parenting or EC and adjustment. Conclusions: Results highlight the utility of assessing stress responses in a multidimensional manner and have implications for intervention programs.