The value and efficacy of laparoscopic colorectal surgery has been validated by large multicenter, randomized, controlled trials. However the results of a large series by a single surgeon in a single center have yet to be reported. We reviewed the short-term outcome of our series of laparoscopic colorectal procedures to better define the learning curve for acquiring these skills. Four hundred four patients with a colorectal neoplasm underwent laparoscopic surgery between August 1998 and December 2005. Surgery was performed under 8 to 10 cm H(2)O CO(2) pneumoperitoneum. Type of operation, time of operation, and estimated blood loss were compared for each level of lymph node dissection, and the rate and reason for conversion to open procedures were determined. Time to passage of flatus, hospital stay, and postoperative complications were recorded. The learning curve for right hemicolectomy, sigmoidectomy, and low anterior resection was calculated. Open conversion was required in 13 patients (3.2%). Uncontrollable bleeding occurred in four cases, and inability to divide the rectum because of adhesions or local invasion occurred in three. The time of operation for D3 level lymph node dissection was longer than for D2 in ileocecal resection, right hemicolectomy, and sigmoidectomy. Estimated blood loss was similar among the different types of operation. Blood loss of last 40 right hemicolectomies was less than in the first 40 cases, and the incidence of intraoperative complications in the first 40 sigmoidectomies was higher than subsequent cases. Time of operation, estimated blood loss, and number of complications did not change over time for low anterior resection. The large series performed by a single surgeon is consistent with large multicenter studies that have validated the superiority of laparoscopic colorectal surgery over conventional open procedures. The learning curve flattens out after about 40 cases of right hemicolectomy and sigmoidectomy.