A 72-year-old female was transported by ambulance to our department to undergo transthoracic surgery. She had previously undergone transabdominal surgery under a diagnosis of adult Bochdalek hernia, but the restoration was believed to have been incomplete. During the transthoracic procedure, a dorsolateral defect of the diaphragm was detected and reinforcement with a Gore-Tex patch was performed. The patient's postoperative course was uneventful. Adult Bochdalek hernia is rare, but it requires immediate surgical intervention. Although transabdominal surgery is generally considered the first line treatment approach to restore Bochdalek hernia, restoration of the diaphragm is occasionally difficult. On the other hand, a transthoracic approach is thought to be effective as it allows for observation of the lung and diaphragm, and easy closure of the diaphragmatic defect. As complete restoration through early surgical intervention is important, a transthoracic approach in conjunction with transabdominal surgery should be considered whenever necessary.