In contrast to gastrointestinal cancer, where a correlation between the expression of different mucin-associated core antigens with clinico-pathological parameters and survival probability, has been established, little is known about their importance in esophageal cancer. Therefore, we characterized esophageal squamous cell carcinomas from 84 patients immunohistochemically by applying monoclonal antibodies (mabs) directed against the Thomsen-Friedenreich (TF) antigen MUC1-bound TF antigen and sialyl-Tn. TF was observed in about 40% of the cases and MUC1-TF epitope in about 75%. Sialyl-Tn was detectable in about half of the carcinomas under study. None of these mabs showed any correlation between binding pattern and clinico-pathological variables, such as TNM stage, lymph node metastasis or grading. However, a strong expression of MUC1-TF epitope as well as sialyl-Tn antigen predicted a poor survival probability. In conclusion, it is suggested that mucin-associated carbohydrate core antigens are involved in the biology and clinical course of esophageal squamous carcinomas.