This phaseII, multicenter, randomized, double-blind, non-comparative study assessed the efficacy and safety of immediate-release octreotide and octreotide LAR, in combination with corticosteroids and standard medical care, on the symptoms of inoperable malignant bowel obstruction (MBO) due to peritoneal carcinomatosis. The primary efficacy endpoint was “success” at day14 defined as a composite endpoint including the absence of a nasogastric tube, and vomiting less than twice per day and no use of anticholinergic agents. Patients in the octreotide arm received octreotide LAR 30 mg intramuscular (im) on days1,29 and57, as well as daily immediate-release octreotide 600 μg per day plus methylprednisolone on days 1 to 6. Placebo-treated patients received methylprednisolone and matched placebo instead of octreotide. Difficulties associated with enrolling patients at palliative-care stage meant only 64patients (instead of the planned 102patients) were randomized, 32to octreotide and 32to placebo. Despite randomization, more patients in the octreotide arm (46.4%) than in the placebo arm (21.9%) had a baseline Karnofsky score less than50. An intention-to-treat analysis showed that in the octreotide and placebo arms, 12(38%) and nine (28%), respectively, patients were successfully treated at day14, which increased to 9/15 (60%) and 7/25 (28%), respectively, among patients with a baseline Karnofsky score greater or equal to50. Octreotide-treated patients reported three drug-related adverse events (AEs), and no drug-related serious AEs or deaths. Octreotide LAR may have a key role in treating patients with a MBO due to peritoneal carcinomatosis, particularly in those with moderately severe disease.