BACKGROUND: The optimal treatment strategy for patients with borderline resectable (BR) esophageal squamous cell carcinoma (ESCC), in which tumors grow very close to the adjacent vital organs, remains unclear. This study evaluated the efficacy of neoadjuvant chemoradiotherapy (NACRT) with cisplatin plus fluorouracil (CF) and irradiation (40 Gy) for these patients. METHODS: The study cohort included 50 patients with BR-ESCC who received NACRT as the initial treatment and were allocated to one of two groups: patients who achieved curative resection (R0 group) or those who did not (Non-R0 group). The overall survival (OS), relapse-free survival (RFS), and pre-therapeutic predictive factors for Non-R0 were evaluated. RESULTS: Among the 50 patients, 22 (44%) achieved curative resection clinically. The median OS was significantly better in the R0 group than in the Non-R0 group (2.4 vs 0.8 years; hazard ratio [HR], 0.29; 95% confidence interval [CI], 0.12-0.67; p < 0.01). The independent predictive factors before NACRT for Non-R0 were higher serum SCC antigen level (p < 0.01) and clinical nodal involvement (p = 0.02). In addition, OS was significantly worse for the patients with higher levels of serum SCC antigen than for those with lower levels (p < 0.01). CONCLUSIONS: Curative resection was achieved for about 40% of the patients who received NACRT for BR-ESCC. Therefore, NACRT could be a useful neoadjuvant treatment option for BR-ESCC. However, a higher serum SCC antigen level before NACRT is predictive of treatment failure and poor survival.