Inadequate patient adherence to prescribed treatment regimens is a major cause of poor clinical outcomes in the treatment of asthma. Among children with asthma, adherence rates are often below 50%. Multiple treatment-, clinician-, and patient-related barriers prevent the achievement of satisfactory levels of adherence. Treatment-related barriers include prolonged and complex regimens, adverse effects, cost, and delayed onset of action. Clinician-related barriers include difficulty in scheduling, treatment by one different care giver after another, perceived clinician disinterest, and time constraints. Patient-related barriers include mild or severe asthma, poor understanding of the need for treatment, insufficient confidence in the clinician or medication, the presence of psychological problems, and low motivation to change behavior. Although all of these factors must be addressed to maximize adherence, patient motivation may be the most critical. This task falls primarily to clinicians (physicians, nurses, staff), and it requires thorough patient and care giver education, more frequent patient contact, and the development of a patient-clinician partnership dedicated to the effective treatment of asthma.