The prognosis of esophageal cancer patients who undergo non-curative resection is very poor. Here, we retrospectively analyzed the factors associated with non-curative resection. Thirty-five patients with cT3 or T4 thoracic esophageal cancer treated with neoadjuvant chemotherapy or chemoradiotherapy followed by esophageal resection were included in this study. Among the 35 patients, 27 underwent curative resection (R0 group), while 8 underwent non-curative resection (R1R2 group). A comparison of the clinicopathological factors between groups revealed no significant differences in presurgical factors. The pathological T factor was significantly deeper in the R1R2 group than in the R0 group (p=0.0086). Histopathological response tended to be higher in the R0 group (p=0.055). An accurate preoperative diagnosis of T factor is important.