We report three cases of terminal-stage ovarian cancer where diatrizoate meglumine and diatrizoate sodium solution (Gastrografin) was effective for malignant bowel obstruction due to peritoneal dissemination. All cases had gastrointestinal symptoms such as nausea, vomiting, abdominal pain, and constipation, showed air-fluid levels and dilation of the small intestine on imaging tests. Therefore, all the cases were diagnosed as bowel obstruction. We initiated oral administration of Gastrografin because the patients failed to show a sufficient response to other drugs such as octreotide. Their gastrointestinal symptoms such as nausea and constipation improved after administration of the drug, and they could continue oral intake. In addition, they were diagnosed as having an incomplete bowel obstruction since radiographic examination 24 hours after administration of Gastrografin confirmed its presence in the large intestine. In all the cases, Gastrografin could be used repeatedly without noticeable side effects. This study suggests that Gastrografin might be useful for evaluating bowel obstruction and improving gastrointestinal symptoms in patients with malignant bowel obstruction caused by terminal-stage ovarian cancer.