Six cases of allergic bronchopulmonary aspergillosis (ABPA) were evaluated. In four cases, diagnosis and steroid therapy were delayed, which resulted in irreversible pulmonary dysfunction. The important points for early diagnosis were: (1) Differentiation from pulmonary tuberculosis, (2) the presence of bronchial asthma was not essential for diagnosis, and (3) fungi other than Aspergillus fumigatus might cause this syndrome.