Background: We present our technique of omental flap transposition performed through a thoracotomy for bronchial stump protection, and employed over 11 years. Methods: Between February 1997 and January 2008, the transdiaphragmatic harvesting of the omentum was performed, using an original technique through a thoracotomy approach, in 45 patients. Forty-three patients (29 male, 14 female), considered at high risk for bronchial dehiscence, simultaneously underwent pneumonectomy and 2 patients (1 male, 1 female) were treated for an early postpneumonectomy bronchopleural fistula by the standard thoracotomy route. The omental flap was mobilized through a radial incision in the diaphragm avoiding an additional laparotomy. The only contraindication for this technique was a previous abdominal intervention. Duration of follow-up ranged between 6 and 102 months (median, 46). Results: There were no complications related to the omentoplasty. Major complications related to pneumonectomy occurred in 4 patients (9%). Perioperative mortality rate was 2.1% (1 of 45). The non-life threatening complication rate was 11.1% (5 of 45). Postoperative hospital stay ranged between 5 and 21 days (median, 8.3) in the 43 patients undergoing prophylactic omentoplasty and was 11 and 14 days, respectively, in the 2 patients receiving omentoplasty after bronchial dehiscence. No neoplastic recurrence on the bronchial stump or late fistula occurred during follow-up. Conclusions: This technique of omental flap transposition for bronchial stump coverage through a thoracotomy is an effective method for the prevention and treatment of postpneumonectomy bronchopleural fistula. The amount of omentum obtained by this technique is appropriate for bronchial reinforcement but not for filling the pleural cavity. This procedure can be performed safely through thoracotomy access avoiding an additional laparotomy.