BACKGROUND/AIMS: Expandable stents were inserted for temporary decompression of the colorectum before single-stage surgery or for palliation. The aim of this study was to evaluate the usefulness of a self-expandable nitinol stent, which can be placed through the working channel of an endoscope, for treatment of malignant colorectal obstructions. METHODS: From May 2000 to April 2001, twenty patients (eleven female, nine male, aged 39~81 years) with malignant colorectal obstructions were treated for relief from the obstructions with endoscopically guided intubation of an expandable nitinol stent through the working channel of an endoscope. Of twenty patients, thirteen underwent placement of the stent for presurgical decompression; seven, for palliative decompression. RESULTS: The site of obstructions were on the rectum (n=8), sigmoid colon (n=6), descending colon (n=2), transverse colon (n=3) and ascending colon (n=1). Stent placement was successful in 18 (90%) of the 20 patients. Failure occurred in two patients with long and tortuous lesions involving hepatic flexure or splenic flexure. All patients tolerated placement of the stent well, with no procedure-related complications. In patients with successful placement of the stent, symptoms of obstruction resolved within 72 hours. Twelve patients underwent the formal bowel preparation and elective single-stage surgery without complications 4~7 days after stent placement. In six patients, the stents provided palliative decompression of the colorectum. There was stent migration in two patients during follow-up. CONCLUSIONS: Placement of a self-expandable nitinol stent through the working channel of an endoscope is technically feasible and safe. Stent placement allowed patients with malignant colorectal obstruction to undergo single-stage surgery in cases of operable disease and to provide palliative decompression in cases of inoperable disease.