Carcinosarcoma of the esophagus is a rare malignant tumor with both carcinomatous and sarcomatous components. We present 3 cases of carcinosarcoma of the esophagus and discuss the histogenesis of the tumors. We performed immunohistochemical studies using various antibodies: anti-cytokeratin, anti-vimentin, anti-smooth muscle actin, anti-p53, and MIB 1 reacting with Ki-67 nuclear antigen.