Bronchocentric granulomatosis is a rare disease, which has to be taken into consideration in the differential diagnostic of pulmonary nodules and tumors. Two cases are presented, in which only open lung biopsy made it possible to get the diagnosis of bronchocentric granulomatosis. A 78-year-old woman presented with multiple small pulmonary nodules with aspergillus colonization, whereas an 83-year-old man presented with a large mass in the left upper lobe. Corticosteroid therapy led to sustained remission in both patients. The case reports will underline that bronchocentric granulomatosis is not a uniform clinical entity, but has variable clinical and radiological appearances. Its former subdivision into two forms differing by the occurrence of asthma with the coexistence of an aspergillus colonization, does not represent the many different manifestations. Until now the etiology of bronchocentric granulomatosis is uncertain. But there are hints, that the granulomatous inflammation might be the uniform response to different causes. The definite diagnosis of bronchocentric granulomatosis can only be made histologically. This mostly requires surgical lung biopsy. With therapy -- either surgery or corticosteroid therapy or the combination of both -- the prognosis is good.