BackgroundPostoperative pneumonia is a common but serious complication in patients with lung cancer. This meta-analysis aims to evaluate the effect of respiratory exercise on reducing postoperative pneumonia in patients with lung cancer and to provide a reliable basis for clinical treatment and nursing of patients with lung cancer.MethodsTwo reviewers searched PubMed, Embase, Web of Science, Cochrane Library, China Knowledge Network, Wanfang, and Weipu databases. We searched for the randomized controlled trials (RCTs) published in Chinese or English on the breathing exercises in patients with lung cancer up to January 30, 2024. The quality of the literature was evaluated with the Cochrane Risk of Bias Tool 2 (ROB 2). RevMan 5.3 software was used for meta-analysis.ResultsEleven RCTs with 1429 patients with lung cancer were included, and 710 patients received breathing exercises. The meta-analysis results showed that breathing exercises could significantly reduce the incidence of postoperative pneumonia [RR = 0.35, 95%CI (0.25, 0.51)], improve the FEV1 [MD = − 0.49, 95%CI (− 0.73, − 0.24)], FVC [MD = − 0.59, 95%CI (− 0.83, − 0.35)] in patients with lung cancer (all P < 0.05). There were significant differences in the incidence of pneumonia for patients undergoing breathing exercises with single exercise time ≥ 15 min (RR = 0.37, 95%CI 0.24 ~ 0.62), breathing exercises for 1 week (RR = 0.29, 95%CI 0.16 ~ 0.55) or for 2 weeks (RR = 0.48, 95%CI 0.28 ~ 0.85) and breathing exercises > 4 times (RR = 0.36, 95%CI 0.23 ~ 0.57) per day (all P < 0.05).ConclusionBreathing exercises have shown the capacity to augment pulmonary function in patients with lung cancer, concurrently mitigating the risk of postoperative pneumonia.