Terminally ill cancer patients with complicated bowel obstructions often have poor quality of life (QOL) due to gastrointestinal symptoms such as nausea and vomiting. Many of these patients are inoperable because of poor general conditions, and half of these patients can't be managed by conventional antiemetics. There are many reports indicating octreotide is effective for these patients. In the present study, 13 patients (5 patients without a nasogastric tube and 8 patients with) were administered octreotide at 300 microg/day by 24 hours continuous subcutaneous infusion. Among the effectively evaluable 10 cases, 6 cases (60.0%) were assessed as effective according to the efficacy criteria based on the JCOG toxicity scale. In the 6 cases who had nasogastric tubes, the nasogastric aspirates decreased from 890 ml (550-1,950) to 480 ml (180-1,790). Vomiting was successfully controlled after the removals of nasogastric tubes in 4 out of 6 cases (66.7%), regarding safety, 2 out of 13 cases (15.4%) showed an excess of liver enzymes but no clinically suspected adverse effect was observed. Octreotide is effective and well tolerated in terminally ill cancer patients with malignant bowel obstruction.