Objective Risk factors for real-word immune checkpoint inhibitor-related pneumonitis in patients with lung cancer were analyzed by systematic analysis. Methods Computerized retrieval of PubMed, EMbase, Web of Science, the Cochrane Library , WanFang Data, CNKI and VIP databases was carried out. Studies were collected from the database establishment to March 2023. Three researchers independently screened the literature, extracted data, and evaluated the risk of bias in the included studies. Meta-analysis was performed using RevMan5.4.1software. Results A total of 18 studies were included with a total of 4 990 patients. The results of meta-analysis showed that, interstitial pneumonia [odds ratio (OR)=9.32, 95% confidence interval (CI) 4.66 - 18.67, P<0.01], smoking history (OR=2.39, 95%CI 1.29 - 4.45, P<0.01), chronic obstructive pulmonary disease (COPD) (OR=5.54, 95%CI 2.96 - 10.36, P<0.01), chest radiotherapy (OR=2.74, 95%CI 1.80 - 4.19, P<0.01), pulmonary fibrosis (OR=7.46, 95%CI 4.25 - 13.09, P<0.01), high programmed death ligand 1 (PD-L1) expression (OR=2.98, 95%CI 1.71 - 5.22, P<0.01), high absolute eosinophil count (AEC) (OR=3.92, 95%CI 2.17 - 7.08, P<0.01) and pembrolizumab (OR=2.90, 95%CI 1.56 - 5.37, P<0.01) were independent risk factors for immune checkpoint inhibitor-related pneumonitis in lung cancer patients. Conclusions Interstitial pneumonia, smoking history, COPD, Chest radiotherapy, pulmonary fibrosis, high PD-L1expression, high AEC and pembrolizumab are independent risk factors for immune checkpoint inhibitor-related pneumonitis in lung cancer patients. Due to insufficient evidence on the risk factors of low albumin, more studies are needed to further identify it.