Abstract Many reports in the recent literature deal with intraperitoneal chemotherapy. Though quite effective for ovarian cancer, it is accompanied by side effects. Extensive adhesion formation after intraperitoneal chemotherapy is one of the side effects to which clinicians must pay attention. In this paper, we present a case of ileus due to extensive adhesion formation about 11 months after cessation of intraperitoneal chemotherapy using cisplatinum (CDDP).