Infections due to Blastomyces dermatitidis are not commonly encountered in children and adolescents. Knowledge of the diagnosis and treatment of this disease is largely based upon experience with adult patients. We recently reviewed our experience with blastomycosis to evaluate the difficulties in diagnosis and treatment of this disease in the pediatric population. Ten patients with blastomycosis were identified during our review, and five had pulmonary disease alone. Of these five patients, four required open-lung biopsy for diagnosis, even though three had previously undergone bronchoalveolar lavage. The response to treatment with the oral azole antifungal agents (ketoconazole, fluconazole, and itraconazole) was limited, and the agent with the greatest success remains amphotericin B. Until more data are available, amphotericin B should be used for complicated and life-threatening cases of blastomycosis. If oral azole agents are used for non-life-threatening cases, patients should be followed closely, and if clinical deterioration occurs or serum levels of medications are not adequate, then amphotericin B should be substituted for the oral azole agent.