Carcinosarcoma of gallbladder is a rare malignant tumor characterized by malignant epithelial and malignant mesenchymal components. Its pathogenesis is unknown and most of carcinosarcomas of gallbladder are associated with poor survival because the disease presents at an advanced stage. A 69-year-old man presented with right upper quadrant pain. The preoperative diagnosis was gallbladder cancer, and thus, curative radical cholecystectomy was performed. Pathologic examination of the surgical specimen revealed that the tumor was composed of carcinomatous components with adenocarcinoma and squamous cell carcinoma, and sarcomatous components with spindle cell sarcoma and chondrosarcoma, which was consistent with a diagnosis of primary carcinosarcoma of the gallbladder. The tumor was found to extend to the pericholecystic fat and no metastasis in regional lymph nodes.