Patients whose asthma symptoms are poorly controlled with the therapies usually recommended for this disease are considered to have "difficult" asthma. Although such patients represent a small proportion of patients with asthma, children who have difficult asthma are at increased risk for morbidity and mortality. Once the diagnosis of asthma is established, caregivers must appropriately categorize and treat the asthma according to the patient's level of symptom severity. The purpose of this article is to present an approach to the management of patients with difficult asthma by (a) searching for alternative diagnoses or conditions that are often associated with asthma, (b) investigating environmental issues, (c) reviewing inhalation techniques, and (d) determining the patient's level of compliance with the prescribed treatment plan and simplifying it whenever possible.