Background Venous thromboembolism (VTE) is a common postoperative complication of lung cancer, but the incidence and risk stratification of postoperative VTE in stage IA non‐small‐cell lung cancer (NSCLC) patients remains unclear, therefore we conducted a single‐center prospective study. Methods A total of 314 consecutive patients hospitalized for lung cancer surgery and diagnosed with stage IA NSCLC from January 2017 to July 2021 were included. The patients were divided into the VTE group and the non‐VTE group according to whether VTE occurred after the operation. The patient's age, operation time, D‐dimer (D‐D) value, tumor pathology, and Caprini score were recorded. The different items were compared and included in logistic regression analysis to obtain independent risk factors, and the area under the receiver operating characteristics curve (AUC) was calculated. Results The incidence of VTE was 7.3%. Significant differences in age, operation time, preoperative and postoperative day 1 D‐D value, neuron‐specific enolase value, forced expiratory volume in 1 second, maximum ventilation, carbon monoxide diffusion capacity, and pathological diameter were noted between the two groups. Age (95% confidence interval CI 1.056–1.216) and postoperative day 1 D‐D value (95% CI 1.125–1.767) were independent risk factors. The incidence of VTE in the low‐, medium‐, and high‐risk groups with Caprini scores was 0%, 7.3%, and 11.5%, respectively. The AUC of the Caprini score was 0.704 (p < 0.05). Conclusions The incidence of postoperative VTE in patients with stage IA NSCLC was 7.3%. Age and postoperative day 1 D‐D value were independent risk factors for VTE. The Caprini score has a certain value in the diagnosis of postoperative VTE of stage IA NSCLC. The incidence of postoperative venous thromboembolism (VTE) in patients with stage IA non‐small‐cell lung cancer (NSCLC) was 7.3%. Age and postoperative day 1 D‐dimer value were independent risk factors for VTE. The Caprini score has a certain value in the diagnosis of postoperative VTE of stage IA NSCLC.