Direct invasion of colorectal adenocarcinoma into adjacent structures occurs frequently, but only rarely is the duodenum involved. This study was undertaken to assess the safety and efficacy of en bloc resection of locally advanced right colon carcinoma invading the duodenum. A retrospective review of 49 patients with locally advanced colon cancer, surgically managed between 2000 and 2005, was performed. Forty-six patients underwent en bloc resection of colon and adjacent organs not involving the duodenum. Three patients with duodenal invasion underwent en bloc partial duodenectomy. The mean operative blood loss, length of stay, postoperative morbidity, and mortality compare favorably between these two groups of patients. Of the 46 patients with en bloc resection of other organs, 27 are alive at 12 to 60 months follow up. Two patients with duodenal invasion are alive without recurrence at 15 and 20 months follow up. En bloc resection of colon cancer invading the duodenum can be performed safely because morbidity and mortality rates are comparable to those attending extended resections of other locally advanced colon carcinomas. Overall survival in patients who underwent surgery with curative intent justifies en bloc duodenal resection in selected patients.