Objective:To investigate the prognostic factors of patients with esophageal squamous cell carcinoma with pulmonary metastasis.Methods:Clinical characteristics of 135 esophageal squamous cell carcinoma patients presenting with pulmonary metastasis after treatment in Zhejiang Cancer Hospital from 2008 to 2018 were retrospectively analyzed. Thesurvival rate was calculated by Kaplan-Meier method. Univariate analysis was performed by log-rank test. Multivariate prognostic analysis was conducted by Cox models.Results:The median follow-up time of 135 patients with esophageal squamous cell carcinoma was 94.2 months (19.5-258.9 months), and 109 patients died (80.7%). The 1-and 2-year overall survival rates were 47.4% and 25.1%, with the median survival time was 11.1 months (7.3-14.9 months). Univariate prognostic analysis showed that age, number of lung metastases, treatment of lung metastases, lymph node metastasis, distant organ metastasis, and the interval between the first treatment and lung metastasis were the prognostic factors of esophageal squamous cell carcinoma with lung metastasis (all P<0.05). Multivariate analysis demonstrated that age and number of lung metastases were the independent prognostic factors for patients with esophageal squamous cell carcinoma with lung metastases (all P<0.05). Conclusions:Age and number of lung metastases are the independent prognostic factors for patients with esophageal squamous cell carcinoma with lung metastases. Surgery or radiotherapy-based regional therapy can enhance clinical prognosis.