Overexpression of RCAS1 (receptor-binding cancer antigen expressed on SiSo cells) protects cancer cells from immune attack and might be related to poor prognosis in several cancers. We investigated the immunoreactivity of RCAS1 and its correlation with clinicopathological features in 95 patients who underwent surgical resection for oesophageal squamous cell carcinoma. Thirty-two of the 95 (33.7%) cases were strongly positive for RCAS1. RCAS1 showed significant correlations with age and stage grouping. Expression of RCAS1 was associated with shorter postoperative survival. Multivariate analysis indicated that RCAS1 positivity was an independent negative prognostic factor. Our study establishes RCAS1 as a novel prognostic marker for surgically resected oesophageal squamous cell carcinoma.