With advances in laparoscopy, various hemostatic procedures have been advocated with variable results. Using currently available tools, some steps in laparoscopic colorectal surgery still represent technical challenges. Our aim was to investigate the feasibility and reliability of the Harmonic Scalpel in laparoscopic colorectal surgery.In this nonrandomized prospective study, 34 consecutive patients (15 males; mean age, 46 (range, 24-80) years) underwent laparoscopic colorectal surgery for benign disease (27 patients) and colorectal cancer (7 patients). Dissection, hemostasis, coagulation, and division of several types of vascular pedicles were performed exclusively with the Harmonic Scalpel. The 10-mm-blade Harmonic Scalpel device was used at full power mode for all purposes through a 10-mm port. Coagulation of vascular pedicles was always achieved with the blades in the flat position. The large pedicles (inferior mesenteric, right and left colic, and ileocolic) were coagulated for 20 seconds in several locations along the length (1 cm) before final division. Smaller vascular pedicles were coagulated for ten seconds before division. When the vein and the artery of major pedicles were divided at their origin, either for malignancy or for technical reasons, they were dissected and coagulated separately. For more limited resection of the mesentery, as in the case of benign disease, vascular pedicles were coagulated together as a single bundle. Operative time, minor or major intraoperative or postoperative hemorrhage, need for conversion to laparotomy, bowel injury, and trocar complications were recorded. All anastomoses were checked on Day 8 by a diatrizoate sodium enema.There was no mortality. Mean operative time was 276 (range, 200-520) minutes. Neither minor nor uncontrollable hemorrhage occurred; no conversion to laparotomy and no vascular or bowel injury were recorded. There was one port-site hematoma. Neither hemoperitoneum, intraperitoneal hematoma, fistula, nor intra-abdominal abscess was observed.Coagulation and division of minor as well as major vascular pedicles in laparoscopic colorectal surgery with the Harmonic Scalpel" are technically easy, feasible, and reliable.