Purpose: The type of surgery or surgical approach for transverse colon cancer treatment largely depends on the tumor location or surgeon's preference. However, extensive lymphadenectomy appears to improve the long-term outcomes of locally advanced colon cancers. This study was designed to compare the short- and long-term outcomes after surgery via the laparoscopic or open approach with radical D3 lymph node dissection in patients with stage II and III transverse colon cancer. Methods: Patients were treated for stage II and III transverse colon cancer between May 2006 and December 2014. This retrospective study evaluated data collected prospectively at a tertiary teaching hospital. Radical D3 lymphadenectomy included the principal middle colic artery nodes. Results: The study included 144 patients among whom 118 (81.9%) underwent laparoscopic surgery. Significantly more patients in the laparoscopic group underwent extended right hemicolectomy compared with the open group (90.7 vs. 65.4%, p = 0.005). The operative time was longer in the laparoscopic group (151.3 vs. 131.2 min, p = 0.021), and the open group had a greater estimated blood loss volume (160.8 vs. 289.3 ml, p = 0.011). Although the groups differed in terms of tumor size (5.8 vs 7.9 cm, p = 0.007), other pathologic outcomes did not differ. The groups did not differ regarding postoperative parameters or disease-free, overall, and cancer-specific survivals. Conclusion: Despite differences in surgical methods and related factors, no long-term differences in outcomes were observed between laparoscopic and open approaches to radical D3 lymphadenectomy in patients with stage II and III transverse colon cancer. [ABSTRACT FROM AUTHOR]