Malignant tumors of the gallbladder are rare, with adenocarcinoma being the most common histological subtype. Carcinosarcoma of the gallbladder, first described in 1907 by Landsteiner, is an extremely rare tumor which comprises less than 1% of the uncommon gallbladder cancers. This unique type of tumor can develop at any major organ, with the uterus being the most common one. Being a tumor that contains epithelial and mesenchymal components, histopathological diagnosis of such rare tumor is a challenging issue. Up to date, there are less than 100 cases of gallbladder carcinoasarocoma reported in the English literature. Therefore, experience and knowledge regarding this rare disease are very limited. Due to the fact that gallbladder carcinosarcoma is a rare and highly forgotten tumor, this article aims to review the English literature to increase awareness of the treating physician to improve diagnosis, management, as well as overall survival.