Background: Postoperative pulmonary complications are responsible for significant increases in hospital cost as well as patient morbidity and mortality; respiratory muscle dysfunction represents a contributing factor.Breathing training is an effective,non-pharmacological intervention but it is unclear how this should be delivered.The aim of this study was to investigate a controlled breathing training program provided by a device on pulmonary function and exercise capacity of patients with NSCLC after completion of their treatment.Patients and methods: This was a single centre,controlled blinded parallel group feasibility study.11 patients with non-smell cell lung cancer (NSCLC) underwent a controlled breathing trainging program provided by a device (CRT group) after completing cancer treatment.The remaining 9 who refused the device were taken as controls (RT group).Pulmonary function tests,6-minute walk test,and dyspnea severity before and after training were retrospectively analyzed.Results: A significant increases between before and after the program were found for FVC (p< 0.05 ),FEV1 (p< 0.05),Borg scale dyspnoea (1.55 verus 0.6,p=0.004),VO2max (p< 0.05) and 6MWD (p<0.01).On the other hand,an increasing trend has also been observed in the RT group,but no significant increases were found for FVC,FEV1,VO2max,and,interesting,a statistically significant improve of Borg scale dyspnoea (p<0.01 vs baseline) and 6MWD (p<0.01 vs baseline) were found.There was a trend for more improvement in Vt and VO2max for the CRT group patients that did reach statistical significance.Conclusions: Postoperative patients with NSCLC after treatment with the controlled breathing training seem to benefit in terms of exercise capacity and pulmonary function in early phase.