The case of a patient with gallbladder carcinoma who had a postoperative residual tumor treated with high-dose-rate intraluminal brachytherapy (HDRIBT) and external radiotherapy (ERT) is presented. HDRIBT (20 Gy/2 fr) was performed at one point 10 mm from the 60Co source on 27 and 34 days after simple cholecystectomy. ERT (30 Gy/15 fr) was also given two weeks after HDRIBT. Following radiotherapy, she has been alive and well without signs of recurrence for one year and ten months as of this writing. HDRIBT combined with ERT is recommended for the treatment of post-operative residual tumors of advanced gallbladder carcinomas.