Teratoma is a germ cell tumor and usually consists of three germ layers. Teratomas are mostly located in the gonads and occurrence of teratoma in extragonadal sites israre. Gastrointestinal tract, particularly colon, is an unusual extragonadal site for teratomas. Extragonadal teratomas arise from totipotent cells in sequestered primitive cell rests. Teratoma cannot be diagnosed on the basis of clinical findings alone, since the histopathologic confirmation is necessary. Cystic teratomas, located in the wall of colon can easily mimic ovarian lesions on radiologic examination. In this case report, we aimed to describe the histopathological findings of an unusual case of mature teratoma in the wall of sigmoid colon which was mimicking an ovarian cystic lesion on radiologic examination.