Objective To investigate the efficacy of early, short-term, low-dose corticosteroid administration for the prevention and treatment of early acute lung injury (EALI) in patients undergoing thoracoscopic lobectomy. MethodsA retrospective analysis was conducted on the clinical data of patients who underwent thoracoscopic lobectomy at the Department of Thoracic and Cardiovascular Surgery, Taihe Hospital, Hubei University of Medicine, from January 2019 to January 2022. Patients were divided into an early steroid therapy group and an observation group based on whether they received corticosteroids in the early postoperative period. In the early steroid therapy group, in addition to standard postoperative care, patients received a low-dose intravenous push of methylprednisolone (80-120 mg/d) for 3 consecutive days. In the observation group, patients received standard postoperative care without intravenous corticosteroids for the first 3 days. Chest plain CT scans were performed on postoperative day (POD) 1 and POD 3 or 4 to evaluate lung injury. CT scores and the incidence of postoperative EALI were recorded. ResultsA total of 521 patients were included (268 males, 253 females; age range: 11-80 years). There were 318 patients in the observation group and 203 in the early steroid therapy group. On POD 1, the incidence of EALI was 16.0% in the observation group and 13.8% in the early steroid therapy group, with no statistical difference (P=0.486). Correspondingly, there was no statistical difference in chest CT scores among EALI-positive patients between the two groups (P=0.927). On POD 3-4, the incidence of EALI was significantly lower in the early steroid therapy group (22.7%) compared to the observation group (33.6%) (P=0.007). Although chest CT scores among EALI-positive patients were lower in the early steroid therapy group, the difference was not statistically significant (P=0.377). The overall incidence of EALI within the first 4 postoperative days was significantly lower in the early steroid therapy group (26.1%) than in the observation group (37.4%) (P=0.007). Radiological progression (defined as new-onset EALI or progression of existing EALI) occurred in 14.8% of the early steroid therapy group, significantly lower than the 28.9% in the observation group (P<0.001). The early steroid therapy group had a shorter postoperative length of stay (P<0.001), while there was no statistical difference in the incidence of poor wound healing between the groups (P=0.762). Conclusion Early postoperative corticosteroid use effectively reduces the incidence of EALI on POD 3-4, lowers the risk of radiological progression, and decreases the overall incidence of postoperative EALI. This is achieved without prolonging the length of stay or increasing the risk of poor wound healing. Therefore, early administration of low-dose corticosteroids is beneficial in suppressing the occurrence and progression of EALI. Its early use is recommended for patients at high risk for postoperative EALI.