Here are reported the therapeutic results of ifosfamide on primary ovarian malignancies in 30 cases which were treated at Kurume University Hospital from September 1978 to December 1980. These cases were advanced or recurrent ones, and histologically, they consisted of serous cystadenocarcinoma in 22 cases, mucinous cystadenocarcinoma in 2, unclassified adenocarcinoma in 1, and malignant teratoma in 5. In the ifosfamide therapy, 2 grams or 40 mg/kg per day were given intravenously for 5 consecutive days, and as observing the blood state and the general condition, it was repeated every 3 weeks. The drug was given from 1 to 7 courses, and the average was 3.3 courses. The effect was evaluated by Koyama-Saito's criteria and Karnofsky's criteria; the response rate was 48% in the adenocarcinoma group and 20% in the malignant teratoma by the former criteria, while the rate was 64% and 20%, respectively, by the latter one. As main side effects, there were seen hemorrhagic cystitis, nausea and vomiting, and the myelotoxicity was low.