Dermoid cyst is congenital benign hamartoma with ectodermal origin and occurs in many parts of the body such as subcutaneous and soft tissue. Most dermoid cysts are solitary and diameter 1 to 4 cm. Very few dermoid cysts become malignant and locate at rectopelvic space rarely. There were less than 10 cases of pelvic dermoid cysts reported in China and less in other countries. Laparotomy was often performed for the pelvic mass with large injuries. Two female cases with mass diameter more than 8 cm resected by laparoscopic and open surgery respectively were reported in this article and postoperative pathological examination suggested as dermoid cyst.