86 cases of solitary air cysts of the lung (6.83% of all maldevelopments) were analyzed. This maldevelopment of bronchial tree is found most often in men (10:7) and more often in the right lung than in the left (18:13). There were no clinical symptoms in 33 (38.37%) patients. Uncomplicated course of the disease was in 51 (59.3%) patients, the disease was complicated by infection in 28 (32.56%) patients. Solitary bronchial cysts were complicated by spontaneous pneumothorax in 8.14% cases, by hemoptysis--in 6.98%. Roentgenography of the chest thorax on two projections and tomography (including CT) are enough for diagnosis of solitary air bronchial cysts. Bronchoscopy, bronchography and APG are not much informative in diagnosis of cysts and should be used on special indications. Cystectomy or cystectomy with partial resection of lung tissue were performed in 67.14% patients with good results.