Teratoma is a type of extracranial germ cell tumor that often occurs and correlates with age and anatomical location. Mature Cystic Teratoma (MCT) is the most common ovarian tumor in children and adolescents. The most common sites for teratomas are the sacrococcygeal region and the ovaries. Laparoscopy is by far the surgical treatment of choice for teratomas. We report a case of a 9-year-old girl with a chief complaint of left lower quadrant abdominal pain 1 week before hospital admission. The patient appears weak and has decreased appetite, accompanied by weight loss, and painful urination. Physical examination of abdominal distension (+), tenderness, and release in the left lower quadrant (+). The patient had not menstruated, and a history of vaginal discharge was denied. On MSCT-scan examination of the abdomen with contrast, a cystic mass was found that adhered to and pushed the surrounding bowel structures in the lower abdominal region. On histopathological examination taken from the left ovary preparation, a macroscopic examination found cyst tissue of 9.5 x 6.5 x 5 cm. The cyst is gray black, filled with blood and a white pulp mass with hair. On microscopic examination found cysts with fibrous connective tissue stroma containing vascular. The treatment is in the form of laparoscopy and after surgery, currently, the patient is in good condition and will be followed up again every 3 months.