An intraarterial high-dose CDDP, using a balloon catheter, has been infused into five patients with a recurrent ovarian cancer. The dose of CDDP was 150 mg-200 mg/body. Two patients experienced a partial tumor regression, whereas three showed no change. With regard to the toxicity, the NAG index (NAG activity/urinary creatinine) rose markedly in all patients, but toxicity was almost similar to that seen from a systemic administration. No significant catheter complication occurred.