Objective: To investigate the impact of extended lymph node dissection on patients with T3 gallbladder cancer. Methods: The clinical data of 45 patients with T3 gallbladder cancer undergoing radical surgery in Taizhou People’s Hospital from January 2009 to December 2014 were retrospectively analyzed. According to the scope of lymphadenectomy, the patients were divided into standard dissection group (20 cases undergoing standard regional lymphadenectomy, namely, dissection of the lymph nodes around the cystic duct and common bile duct and hepatoduodenal ligament), and extended dissection group (25 patients undergoing extended regional lymphadenectomy, namely, standard regional lymphadenectomy plus lymphadenectomy of the posterior superior region of the head of the pancreas, or additional para-aortic lymphadenectomy for those with positive finding in rapid pathological diagnosis). The incidence of postoperative complications and survival conditions of two groups of patients were compared. Results: No perioperative death occurred in any of the groups. The incidence of postoperative complications was 15% (3/20) in standard dissection group and 20% (5/25) in extended dissection group, which showed no statistical difference (P>0.05). The 1- and 3-year cumulative survival rate and median survival time was 8%, 0 and 9 months in standard dissection group, and 100%, 44% and 28 months in extended dissection group, and the survival rate in extended dissection group was significantly higher than that in standard dissection group (χ2=45.921, P<0.05). Conclusion: The extended regional lymphadenectomy focusing on lymph nodes in the posterior superior region of the head of the pancreas and para-aortic lymph nodes may effectively improve the survival of the patients with T3 gallbladder cancer without an increase of surgical complications under the premise of radical resection of the primary lesion.