Abstract: The present study aimed to examine the efficacy of surgical treatment for pT4 squamous cell carcinoma in the mid-thoracic esophagus. Methods: A retrospective study was performed on 45 patients with pT4 mid-thoracic esophageal squamous cell carcinoma. The patients were accepted for surgical treatment from January 2003 to January 2006. All patients were supposed to undergo complete resection according to the thoracic computer tomography. There were two different surgical approaches. One was the modified Ivor-Lewis esophagectomy, and the other was esophagectomy via the left thoracic pathway. The Kaplan-Meier method was performed to calculate the survival rate. The log-rank test was performed to compare the survival rates. Cox regression multivariate analyses were performed to identify independent prognostic factors. Results: All T4a patients underwent complete resection. Among the 16 T4b patients, 6 underwent complete resection (combined resection of the invaded organ) and 10 underwent palliative resection or exploration. The incidence rate of perioperative complications was 35.6%, and 2 patients died. The overall 5-year survival rate of the 45 patients was 17.7%. The 5-year survival rates of the T4a and T4b patients were 24.1% and 6.4% ( P < 0.01 ), respectively. The 5-year survival rate of the patients with complete resection was 23.5%, and that of the patients with palliative resection/exploration was 0% ( P < 0.01 ). The 5-year survival rate of patients with palliative resection and with exploration were both 0 ( P = 0.85 ). The 5-year survival rates of patients treated with and without adjuvant therapy were 21.2% and 9.1% ( P = 0.98 ), respectively. According to the Cox regression analyses, both the incomplete tumor resection ( P < 0.01 ) and lymphatic metastasis ( P < 0.01 ) were independent risk factors of prognosis. Conclusion: After complete resection, T4a patients with tumors invading the mediastinal pleura, had better prognoses than T4b patients. For T4b patients, the surgical method must be carefully chosen because of the high risk involved. There was no significant difference patient survival between palliative resection and explorationing.