Aspergillus fumigatus can cause a number of lung diseases. One of them is allergic bronchopulmonary aspergillosis (ABPA) characterized by pulmonary eozynophilia, asthma, an allergic type of immune response in the bronchi and proximal bronchiectases. ABPA was recognised in 28-years old man (round shadows in the lung, obturated bronchus with mucoid impaction, positive skin tests with aspergillin and presence of precipitins to Aspergillus fumigatus, elevated serum IgE level). Patient was treated for 6 months with corticosteroids. After 2 years of regression there was an exacerbation of ABPA was recognised. The steroid therapy was repeated.