In June 1986 we initiated an intra-peritoneal (IP) mitoxantrone chemotherapy trial as consolidation treatment for ovarian carcinoma in CR or PR after induction therapy (surgery + CHAP combination chemotherapy). Thirty-two patients received 25 mg IP mitoxantrone every 3 wk for 6 months. The most frequent side-effects were abdominal pains; haematological toxicity was minimal. The response was assessed by third-look surgery. In group I patients (patients in histological complete remission at second-look surgery) 12 of 14 evaluable patients remained in CR at the time of third look. Ten of the 12 patients are still alive with no evidence of disease (NED) with a median follow-up of 9.7 months after completion of treatment. In group II patients (microscopic residual disease at second-look surgery), 7 of 9 evaluable patients entered in CR at the time of third look; 6 of the 7 are still alive with NED and with a median follow-up of 14.3 months. In 7 group III patients (macroscopic residual disease at the time of second look) no response to IP therapy was observed and all patients progressed. We conclude that IP mitoxantrone is a valuable consolidation treatment for patients in CR or with minimal residual disease; further follow-up is necessary to assess the impact on duration of remission and survival.