Gallbladder cancer is the most common biliary tract malignancy and has poor 5-year survival. Incidental gallbladder cancers have good survival after cholecystectomy because most are diagnosed at an early stage. The latest The American Joint Committee on Cancer guideline (8th edition, 2017) has changes in the criteria for T and N staging, leading to new surgical approaches for gallbladder cancer. In the new guideline, negative resection margins with adequate clearance for regional lymph nodes is the main principle of curative treatment.