Objective: Children's health beliefs are significantly related to their adherence; however, pediatric literature has rarely tested health-related theories as a whole. The goal of the present study was to evaluate the use of the health belief model (HBM) in understanding children's adherence, both globally and to individual treatment components. Method: Thirty-three patient-parent dyads completed questionnaires regarding health beliefs and adherence to medical regimens. Results: Multiple linear regressions found a significant relationship among the HBM variables and reports of global adherence for children and parents. For children, the HBM variables were significantly related to adherence to aerosol medications, aerosol antibiotics, metered dose inhalers, and vitamins. For parents, the HBM variables were significantly related to children's adherence to airway clearance, oral antibiotics, and vitamins. Paired sample "t" tests found children and parents had significantly discrepant heath beliefs. Conclusion: These findings provide further support for the HBM in evaluating pediatric adherence, with evidence that barriers and cues to action may be targets for early intervention. Future research using this model to identify a comprehensive way to assess, understand, and elicit change in the adherence to medical regimens for youth with chronic illness would be beneficial.