The authors present a rare case of congenital diaphragmatic Bochdalek hernia in an adult stimulating left pleural effusion. The diagnosis of left pleural effusion was made on the basis of conventional chest X-ray and ultrasonography. The definitive diagnosis of Bochdalek hernia was made by left video-assisted thoracoscopy. The patient was successfully treated operatively by conventional surgery--a combination of left thoracotomy and median laparotomy. The reported case supported the view that Bochdalek hernia in adults presents usually with atypical chronic abdominal and respiratory symptoms. Surgical treatment should best be performed, according to the authors, by competent surgeons with good command of both the thoracic and abdominal approaches to the diaphragm.