To predict the postoperative pulmonary function using ventilation-perfusion scintigraphy and explore its feasibility in evaluating surgical risk for lung cancer patients with borderline pulmonary functions [forced expiratory volume in 1 s (FEV₁)<2.0 l for pneumonectomy or <1.5 l for lobectomy]. Twenty lung cancer patients (52-86 years, four women, 16 men) with borderline pulmonary functions were included in this study. Planar ventilation scans with Tc-diethylenetriamine pentaacetic acid aerosol and perfusion scans with Tc-macroaggregated albumin were performed before surgery. Pulmonary function test was performed 1 week before surgery for all patients and 2 months after surgery for 12 patients. The predicted postoperative FEV₁ (ppoFEV₁) values were calculated using Neuhaus equations and compared with FEV₁ values after surgery. There was no significant statistical difference between the ppoFEV₁ values resulting from the ventilation scan (ppoFEV₁-V) and the ppoFEV₁ values resulting from the perfusion scan (ppoFEV₁-Q): (1.153 ± 0.227) l versus (1.204 ± 0.210) l (n=20, t=0.045, P>0.05). No statistically significant difference existed between the ppoFEV₁-V values and the postoperative FEV₁ values: (1.238 ± 0.200) l versus (1.28 ± 0.146) l (n=12, t=0.557, P>0.05), or between the ppoFEV₁-Q values and the postoperative FEV1 values: (1.302 ± 0.161) l versus (1.28 ± 0.146) l (n=12, t=0.288, P>0.05). Both ppoFEV₁-V values and ppoFEV₁-Q values fairly correlated with the postoperative FEV₁ values (r=0.765, 0.674; t=3.756, 2.885, P<0.01, P<0.01). Ventilation-perfusion scans can predict postoperative pulmonary function and help evaluate the risk of surgery for lung cancer patients with borderline pulmonary functions.