Perforations of large bowel are rare but severe complications, mainly of colorectal cancer and colonic diverticulitis. The choice of the surgical procedure is still debated. We retrospectively studied peritonitis caused by large bowel perforation to assess predictors of mortality and safety of primary resection and anastomosis. We investigated 59 patients with large bowel perforation treated surgically as emergency cases: 18 patients underwent primary resection and anastomosis, 36 had primary resection of the diseased part of bowel without anastomosis, and 5 patients had non-resective procedures. The severity of peritonitis was assessed using Hinchey's classification and the Mannheim peritonitis index (MPI). Overall mortality was 16.9%. MPI score was significantly lower for survivors vs. non-survivors, and for patients with resection and anastomosis vs. those who underwent resection without anastomosis (p<0.001). The mortality rate was 11.1% for primary resection with anastomosis, and 22.2% for primary resection without anastomosis. No patient with MPI less than 25 died, while 10 (38.5%) of the patients with MPI of 26-36 died. In conclusion, a radical aggressive approach is recommended for most patients with large bowel perforation. Mortality and morbidity are closely related to the extent of intraperitoneal infection and the incidence of postoperative complications is higher in patients with perforation due to non-malignant causes.