High levels of effortful control have been shown to protect children from negative health outcomes following early adversity. In this study, we tested whether effortful control already moderates the effects of parenting stress on children’s cortisol levels in toddlerhood. In 31 families, parental reports of parenting stress and toddlers’ effortful control were obtained via questionnaires, and toddlers’ salivary cortisol levels were assessed twice in the morning and once in the evening. Contrary to expectations, parenting stress was not related to toddlers’ cortisol levels, and effortful control did not moderate these non-significant associations. Higher levels of parenting stress were related to lower levels of toddler’s effortful control (r = -.43, p =.016). Future work may examine at what age effortful control starts to influence an individual’s psychobiological adaptation in the context of (parenting) stress, which may inform prevention and intervention approaches.