Standard treatment for unresectable locally advanced esophageal cancer is definitive chemoradiotherapy (dCRT). Although salvage esophagectomy is the only curative treatment available following dCRT failure, the appropriate candidates for salvage esophagectomy remain unclear. Three hundred seventeen patients who underwent dCRT from April 2004 to December 2016 were stratified into three study groups-a complete response (CR) group, chemotherapy or best supportive care (BSC) group, and salvage esophagectomy group-and compared. We also investigated the clinical outcomes and prognostic factors of salvage esophagectomy. Seventy-one patients (22.4%) achieved CR after dCRT, 18 patients (5.7%) underwent salvage esophagectomy, and 228 patients (71.9%) underwent palliative chemotherapy or BSC. The 5-year overall survival (OS) rates of the CR group, salvage esophagectomy group, and chemotherapy or BSC group were 83.0%, 51.6%, and 1.3%, respectively. Salvage esophagectomy recipients had a worse OS rate than CR patients (p < 0.001) but a better OS rate than those in the chemotherapy or BSC group (p < 0.001). Incomplete resection was the only significant variable associated with poor OS on univariate Cox proportional-hazards analysis (hazard ratio: 7.633, 95% confidence interval: 1.692-34.482; p = 0.008). Patients with tumors in the upper thoracic esophagus were more likely to undergo incomplete resection (p = 0.011). Patients who achieve R0 resection are good candidates for salvage esophagectomy regardless of their response to dCRT. Those with upper thoracic esophageal tumors are at risk of incomplete resection; careful attention is required when considering these patients for salvage esophagectomy.