Importance: Optimization of surgical outcomes after colectomy continues to be actively studied, but most studies group right-sided and left-sided colectomies together. Objective: To determine whether the complication rate differs between right-sided and left-sided colectomies for cancer. As a secondary analysis, we investigated hospital length of stay. Design: We identified patients who underwent colectomy for colon cancer in the 2005-2008 American College of Surgeons National Surgical Quality Improvement Program database and stratified cases by right and left side. Preoperative, intraoperative, and postoperative factors were compared. Multivariable techniques were used to assess the impact of the side of colectomy on operative outcome measures, adjusting for covariates. Setting: Hospitals within the American College of Surgeons National Surgical Quality Improvement Program database. Patients: We identified 4875 patients who underwent elective laparoscopic or open colectomy for right-sided or left-sided colon cancer in the database. Main Outcomes and Measures: Major complications and surgical site infection (SSI) rates. Results: In the 4875 colectomies studied, a laparoscopic approach was used in 42% of cases and at similar frequency in right-sided and left-sided colectomies. Thirtyday mortality (1.5%) was similar in both groups. Major complications were seen in 17% of patients in each group. Superficial SSI was more likely to occur in patients who underwent left-sided colectomy (8.2% vs 5.9%). Among patients with postoperative sepsis or deep or organ space SSIs, more patients in the left-sided colectomy group underwent reoperation compared with the right-sided colectomy group (56% vs 30%). Laparoscopic right-sided colectomy patients were more likely to have a prolonged hospital length of stay than laparoscopic left-sided colectomy patients (odds ratio, 1.39; 95% CI, 1.09-1.78). Conclusions and Relevance: The outcomes after colectomy for cancer are comparable in right-sided and leftsided resections, except for in the case of superficial SSI, which is less common in right-sided resections. Further research on SSI after colectomy should incorporate right vs left side as a potential preoperative risk factor.