We report the case of a 21-year old man with a long-standing history of severe asthma and allergic rhinosinusitis who developed progressive worsening of dyspnea, wheezing, productive cough, and nasal obstruction, with little response to antibiotics and repeated short courses of oral corticosteroids. A diagnosis of allergic bronchopulmonary aspergillosis was made on the basis of a combination of clinical, laboratory and radiographic findings.Treatment with oral methylprednisolone and itraconazole resulted in an improvement in symptoms, lung function and computed tomography results, as well as in a decrease in total serum immunoglobulin E. This case report highlights the importance of a high degree of clinical suspicion in order to diagnose and treat allergic bronchopulmonary aspergillosis in patients with a long-standing history of severe asthma as early as possible as this has a major impact on prognosis. It also highlights the effectiveness of itraconazole as adjunctive therapy to systemic corticosteroids in this condition.