Bowel stent insertion has a variety of complications one major of which is colonic perforation. The purpose of this article is to reveal two cases with delayed colonic perforation after stent placement to relieve bowel obstruction caused by rectal cancer. The first patient was a 55 year-old man who was a candidate for stent placement to avoid palliative surgery and relieve his bowel obstruction. Although the procedure resulted in complete relief of patient symptoms, but he returned with signs of peritonitis 10 days after the stent placement. A perforation was found at rectosigmoid junction on laparotomy. The second patient was a 60 year-old man who underwent a successful stent placement and returned 3 months later with a complaint of abdominal pain that showed up to be due to a rectal perforation on investigations. In conclusion, bowel perforation following stent placement can be a major complication, so close follow-up is necessary to detect it as soon as possible and prevent it from becoming an irreparable complication.