Background: Patients with gallbladder cancer (GBCA) often present at the advanced stages and major hepatectomy with/without enbloc adjacent organ resection is sometimes necessary to achieve cancer negative margin. Given poor prognosis of advanced GBCA in general, the role of such aggressive operation remains controversial. Method: Patients who underwent resection for T3+ GBCA with curative intent at our institution from Jan. 2006 through Jun. 2019 were included. The short- and long-term outcomes for patients who underwent major hepatectomy (hemi-hepatectomy or greater) or additional organ resection (extended resection) were evaluated and compared with the outcomes for those who underwent standard radical cholecystectomy. Result: Total 49 patients were identified and included. Twenty-nine patients underwent extended resection (ER), and the remainder underwent standard radical cholecystectomy (RC). The types of extended resection included major hepatectomy (n=24, 49%), pancreaticoduodenectomy (n=12, 25%), partial duodenectomy (n=9, 18%), partial colectomy (n=7, 14%). Age and incidence of jaundice were significantly greater in ER group. While ER was applied for more advanced tumor (greater pT and pN) compared to RC, comparable R0 resection rate was achieved by ER (83% vs 80% for RC, p=1.0) with acceptable severe complication rates (35% vs 10%, p=0.09). During the study period, 37 patients (76%) developed disease recurrence and 92% of them were distant metastasis. Median recurrencefree survival (RFS) and overall survival (OS) were not different between the patients after ER and RC (RFS: 9 mo vs 10 mo, p=0.74, OS: 21 mo vs 22 mo, p=0.76) Conclusion: While long-term outcomes for patients with resected GBCA T3 or greater remains unsatisfactory, extended resection could be one option to achieve R0 resection for advanced tumors with local invasion. Extended resection should be performed under strict preoperative evaluations for operative risk and preparations.