Objective To investigate the etiology, symptoms, diagnosis, surgical treatment, and outcomes of acute necrotizing mediastinitis (ANM) in order to guide future diagnosis and treatment of ANM. Methods The clinical data of patients with ANM referred to West China Hospital, Sichuan University from March 2012 to April 2021 were retrospectively analyzed. The etiology, clinical manifestations, demographic characteristics, bacterial culture results, surgical approach and prognostic factors of these patients were summarized. ResultsA total of 176 patients were enrolled in this study. The median age was 60 ( 0-84) years. There were 124 (70.5%) males and 52 (29.5%) females. The most common origin of infection was neck (n=66, 37.5%). The most common symptom was fever (n=85, 48.3%). Streptococcus constellatus represented the most common pathogens in secretion culture. Surgical treatment was administered to 119 (67.6%) patients through different approaches, including 54 (30.7%) patients of cervical approach, 9 (5.1%) patients of thoracotomy, 18 (10.2%) patients of video-assisted thoracoscopic surgery (VATS), 7 (4.0%) patients of cervical combined with thoracotomy, 30 (17.0%) patients of cervical combined with VATS, and 1 (0.6%) patient of subxiphoid approach. Among this cohort, 144 (81.8%) patients were cured, while 32 (18.1%) patients died. Age-adjusted Charlson comorbidity index (OR=2.95, P=0.022), perioperative sepsis (OR=2.84, P=0.024), and non-surgical treatment (OR=2.41, P=0.043) were identified as independent predictors of poor outcomes. Conclusion For patients with corresponding history and manifestations of ANM, it is crucial to go through imaging examination to confirm the presence of an abscess and guide the selection of surgical approach. Once the diagnosis of ANM is made, it is imperative to promptly perform surgical intervention for effective drainage. Our study highlights the significance of age-adjusted Charlson comorbidity index, perioperative sepsis and surgical treatment in predicting patients’ outcomes.