Objective To analyze the correlations between the thoracic electrical impedance tomography (EIT)-derived parameters global inhomogeneity (GI), center of ventilation (COV), regional ventilation delay (RVD), and atelectasis in hospitalized patients, and to explore their effectiveness in evaluating atelectasis. Methods The clinical data of 140 hospitalized patients monitored by thoracic EIT between Sep. 2024 and Jan. 2025 were retrospectively analyzed. Patients were assigned to 2 groups based on chest computed tomography confirmation of atelectasis within the preceding short-term period during EIT monitoring: non-atelectasis group or atelectasis group. The algorithm software designed with MATLAB was used to acquire GI and COV. RVD was obtained through analysis with the Dräger EIT Data Analysis Tool 6.3 software, and patients’ general data were concurrently documented. Comparative analysis of EIT-derived parameters between groups was conducted. Multivariate logistic regression analysis was employed to investigate the correlations of GI, COV, and RVD with atelectasis, while receiver operating characteristic curve analysis was performed to assess the efficacy of EIT-derived parameters in evaluating atelectasis. Results A total of 140 patients were enrolled, with 19 (13.6%) cases presenting atelectasis. Compared to the non-atelectasis group, the atelectasis group demonstrated significantly higher proportions of male patients and cardiovascular disease and thoracic surgery (non-pulmonary) histories, lower body mass index (BMI), and alongside elevated GI and RVD values with reduced COV (all P＜0.05). Multivariate logistic regression analysis revealed that GI, COV, and RVD maintained independent associations with atelectasis after adjusting for age, gender, BMI, pleural effusion, and emphysema (odds ratio ［OR］＝ 1.39, 95% confidence interval ［CI］ 1.20-1.67; OR＝0.85, 95%CI 0.75-0.96; OR＝1.22, 95%CI 1.09-1.39; all P＜0.05). The area under curve (AUC) values of GI, COV, and RVD for evaluating atelectasis in hospitalized patients were 0.82, 0.80, and 0.82, respectively (while RVD demonstrated a higher AUC, its clinical applicability was influenced by respiratory patterns). Conclusion Thoracic EIT-derived parameters GI and COV demonstrate significant correlations with atelectasis and may serve as valuable indicators for evaluating atelectasis in hospitalized patients.