Mature cystic teratoma or dermoid cyst is the most common germ cell tumour of the ovary. The incidence ranges from 5 to 25% of all ovarian neoplasms out of which 13.7% are bilateral. Teratomas usually occur in the ovaries but they may be seen in other sites known as extragonadal teratomas the incidence of which is only 0.4%. Teratomas are usually benign but they may turn out to be highly malignant. Torsion is known to be the most frequent complication of ovarian teratomas followed by autoamputation. Teratomas are classified as “Mature” and “Immature” by WHO. Teratomas show good prognosis specially the mature ones. Surgery and follow up remains the standard approach. We report a case of mature cystic teratoma in the right ovary of a 28 years old nulliparous woman.