Abstract: Objective To explore the impact of sleeve gastrectomy on lung function in obese patients, and to investigate the correlation between changes in body mass index (BMI), neck and abdominal circumference, and improvements in lung function indicators after weight loss.Methods A total of 60 obese patients who underwent sleeve gastrectomy at the Affiliated Hospital of Xuzhou Medical University from October 2022 to October 2024 were selected. The changes in lung function and symptom scores before and after weight loss surgery were compared by Paired t-tests or Wilcoxon signed-rank tests. Spearman or Pearson correlation analysis was conducted to determine the correlation between changes in BMI (ΔBMI), neck circumference (Δneck), abdominal circumference (Δabdominal), and improvements in lung function.Results Three months after weight loss surgery, the patients showed significant reductions in BMI, neck circumference, and abdominal circumference. Symptoms such as sleepiness, cognitive impairment, anxiety, and depression were significantly improved, with statistically significant differences (P<0.05). Lung function parameters, including vital capacity (VC), forced vital capacity (FVC), forced expiratory volume in the first second (FEV1), FEV1/FVC ratio, peak expiratory flow (PEF), maximal mid-expiratory flow (MMEF), total lung capacity (TLC), and diffusing capacity of the lung for carbon monoxide (DLCO), were significantly improved after surgery compared with preoperative values (P<0.05). Correlation analysis showed that ΔBMI and Δabdominal circumference were positively correlated with ΔVC, ΔFVC, ΔFEV1, ΔFEV1/FVC, ΔPEF, ΔMMEF, ΔTLC, and ΔDLCO (P<0.05). ΔNeck circumference was positively correlated with ΔVC, ΔFVC, FEV1, and ΔTLC (P<0.05), but no significant correlation was found with ΔFEV1/FVC, ΔPEF, ΔMMEF, and ΔDLCO (P>0.05).Conclusions Sleeve gastrectomy effectively improves lung ventilation and gas exchange function in obese patients.