Objective: Draining of the chest cavity with two chest tubes after pulmonary lobectomy is a common practice. This study aimed to investigate whether using two tubes after a pulmonary lobectomy is more effective than using a single tube. Method: This prospective randomised study included 100 consecutive patients who underwent lobectomy or bilobectomy for any pathological condition between May 2006 and November 2007. In the 50 patients in the 'single-tube group', only one 32 F chest tube was inserted, and in the 50 patients in the 'doubte-tube group', two 32 IF chest tubes were inserted. Pre-, intra- and postoperative variables in both the groups were compared. Results: The pre- and intraoperative characteristics of the patients were similar in both groups. The mean amount of drainage from chest tubes was 600 +/- 43.2 cc in the single-tube group and 896 +/- 56.2 cc in the doubte-tube group (p, < 0.001). The mean values of postoperative pain assessed on the visual analogue scale (VAS) in the early (second day) period were 4.28 +/- 0.21 in the single-tube group and 5.10 +/- 0.23 in the double-tube group (p = 0.014). The VAS scores in the late (second week) period were 1.48 +/- 0.13 in the single-tube group and 2.00 +/- 0.17 in the doubte-tube group (p = 0.01). All other related parameters were similar in both groups. Conclusions: Insertion of two chest tubes is not more effective than the insertion of a single chest tube after pulmonary lobectomy. Moreover, using a single tube is in fact more effective than using two tubes in that it causes less postoperative pain and less pleural fluid loss. (C) 2008 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.