ObjectiveTo determine if comfort level was associated with chest tube size(16F or 28F) among lung cancer patients with video-assisted thoracoscopic surgery (VATS) lobectomy. MethodsWe performed VATS lobectomy for 163 patients with lung cancer in our hospital between February and May 2014. There were 70 males 93 females. The patients were allocated into two groups including a 28F group and a 16F group. There were 75 patients at age of 53.18±14.73 years with insertion of one chest drain of 28F in the 28F group. And there were 88 patients at age of 56.62±12.62 years with insertion of one chest drain of 16F in the 16F group. Heart rate and variation of pulse, breathing rate and variation of breathing rate, pain scores, comfort level, and activities daily living (ADL) of the two groups were compared. ResultsThere was no significant difference in the patient characteristics and operation data between the two groups. There were statistical differences in variation of heart rates on the 1st day, 2nd day, and 3rd day after operation between the 16Fgroup and the 28F group (9.67±3.33 times/min vs.18.54±5.33 times/min, P=0.037; 7.89±2.88 times/min vs. 19.01±4.67 times/min, P=0.045; 7.67±3.01 times/min vs. 20.88±5.34 times/min, P=0.021). The percentage patients of mild pain in the 16F group (77.65%) was higher than that in the 28F group (49.78%, P=0.023) with a statistical difference. The independent ambulation and comfort level in the 16F group(67.05%, 67.05%) were significant higher than those in the 28F group (45.78%,55.11%, P=0.023, P=0.026). ConclusionOur findings suggest that drainage via a small-bore chest tube provides meaningful postoperative comfort level in the patients with VATS lobectomy.