In a consecutive series of 38 patients over 5 years, who required emergency surgery for obstructing left colonic carcinoma, 24 had primary bowel resection with immediate anastomosis, after intraoperative anterograde colonic irrigation. Complete colonic obstruction was present in all cases. There were 7 Dukes B tumors, 11 Dukes C tumors and 6 Dukes D tumors. The operative mortality was 8.3% (2 patients, with one from anastomotic leakage), anastomotic leakage rate was 4%. Superficial wound infection occurred in 4% of patients. The median postoperative hospital stay was 19.5 days. The Kaplan-Meier survival curve showed a 41% survival rate after 5 years. This technique was found to be safe and effective to perform a primary anastomosis, without requiring temporary colostomies, after emergency resection of selected left colonic carcinoma obstruction.