During the past 28 years, 55 bronchopleural fistulas (BPFs) have developed after pulmonary resections for 52 primary and 3 recurrent lung cancers at the National Cancer Center Hospital, Tokyo. During the same period, there were 2446 pulmonary resections for primary lung cancer, the incidence of BPF being 2.1%. As an operative mode of initial resections, pneumonectomy (26 cases) was most common, followed by lobectomy (20 cases), bronchoplasty (8 cases), and stump resection for recurrence (1 case). The following predisposing risk factors for BPF development were identified: resection for locally advanced lung cancer (80.8%); residual carcinomatous tissue at the resected end of bronchus or anastomosis line (29.1%); hypoalbuminemia, diabetes, or steroid administration (20%); pre- and postoperative adjuvant therapy (49.1%). Seven cases received no treatment for BPF because of sudden deaths by massive airway bleeding (5 cases), worsening pneumonia (1 case), and spontaneous recovery (1 case). Remaining 48 cases underwent treatment; tube thoracostomy only in 7 cases and surgical interventions in 41 cases, one case of which was lost during rethoracotomy due to vascular rupture. Initial surgical interventions were composed of combinations of the following procedures; direct re-suture of fistula (16 cases); amputation of the stump and re-closure (3 cases); completion pneumonectomy (6 cases); reinforcement and wrapping of fistula (27 cases); thoracoplasty (29 case). Among these 40 surgical repairs, fistula was successfully closed in 11 cases. In 5 cases, the fistula closure could be achieved after subsequent surgical procedures. Direct re-suture was successful only in 4 cases. In spite of various kinds of treatment, overall prognosis was quite poor; 37 cases died of BPF-related complications (67.3% mortality).(ABSTRACT TRUNCATED AT 250 WORDS)