The past three decades have seen a shift in approaches to studying health and illness behavior from disease-oriented medical models to integrated bio-psycho-social models. The factors leading to asthma health disparities between Mexican and Puerto Rican children are complex and not well understood. Illness representations, the associated treatment decisions (CAM and controller medication use), and the influence of acculturation on these processes, are three factors requiring additional scrutiny. The Common Sense Model of Illness Representation is an integrated model that takes into account environmental, social, and cultural factors as well as patients' beliefs about health and illness. Because parents are the gatekeepers for their children's healthcare and ultimately make the final treatment decisions, it is parents' representation of their children's illness that influences treatment decisions and children's asthma health outcomes.