Experience with 36 ovarian tumors operated on from 1923 to 1958 is reported. Only 5 (14%) of the tumors were malignant. The most common complaint was abdominal pain which was acute or subacute in 10 cases which were associated with a twisted pedicle. In this group, signs and symptoms strongly suggested an acute appendicitis. Abdominal enlargement sometimes associated with chronic abdominal pain was the next most common complaint. X-rays were of more help in ruling out other possible causes of abdominal pain or mass than in making a positive diagnosis, although calcification in a teratoma would be demonstrated. None of the children in this group showed endocrine disturbances. Surgical removal through a right or left paramedian incision is preferable but because the disease is often thought to be associated with the appendix, a McBurney incision may be extended for its removal. This is possible because the ovary in the young child is abdominal rather than pelvic in location. In the malignant group, radiotherapy was used only where removal was incomplete. In this group, 2 of the 5 children remained alive and well 5 and 23 years after operation. Children with benign tumors uniformly did well, there being 1 death from post-operative peritonitis. Nineteen of the 31 benign ovarian tumors were classified as teratoma, 5 were simple cysts associated with torsion and 5 were classified as serous cystadenomata.