The Clinical Outcomes in Surgical Therapy trial demonstrated that laparoscopic colectomy (LC) was equivalent to open colectomy (OC) for 30-day mortality, time to recurrence, and overall survival in colon cancer (CC) patients. Current use of LC for CC is not well known. Surgical data were reviewed for all patients randomized into a national phase III clinical trial for adjuvant therapy in stage III CC (North Central Cancer Treatment Group trial N0147). Colon resections were grouped as open (traditional laparotomy) or laparoscopic, including laparoscopic; laparoscopic assisted; hand assisted; and laparoscopic converted to OC. Statistical methods included nonparametric methods, categorical analysis, and logistic regression modeling. A total of 3,393 evaluable patients were accrued between 2004 and 2009; 53% were male, median age was 58 years, 86% were white, and 70% had a body mass index >25 kg/m(2). Two thousand one hundred thirteen (62%) underwent OC. One thousand two hundred eighty (38%) were initiated as laparoscopic procedures, 25% (n= 322) were laparoscopic, 32% (n = 410) were laparoscopic assisted, 26% (n= 339) were hand assisted, and 16% (n= 209) were LC converted to OC. Significant predictors of LC (vs OC) in multivariate models were T stage (T1 or T2 vs T3 or T4; p= 0.0286), and absence of perforation, bowel obstruction, or adherence to surrounding organs (p < 0.01 each). Increasing rates of LC were observed over time, with LC eclipsing OC in 2009 (p < 0.0001). Surgical efficacy, measured by lymph node retrieval, was similar, with the mean number of lymph nodes retrieved higher in the LC group (20.6 vs 19.5 nodes; p= 0.0006). This study demonstrated a steadily increasing use of LC for the surgical treatment of CC between 2004 and 2009, with LC preferred by study completion. Surgical efficacy was similar in stage III CC patients.