Ovarian tumors in young females under the age of 20 years in Songklanagarind Hospital from February 1983 to March 1989 were evaluated. The total number of patients was 47, with a 4.0 per cent incidence of ovarian tumors in all age groups. Germ cell tumor was the most common tumor (59.6%) and 60.7 per cent were malignant. The chief presenting symptom was abdominal distention or mass, with 17.0 per cent of torsion. Ascites and solid consistency of tumors suggested its malignant potential. Surgery was the treatment for all patients with a conservative approach in the majority of cases and supplemented with chemotherapy and/or radiotherapy in malignant cases.