HYPOTHESIS: Precise preoperative staging for gallbladder carcinoma is difficult, despite recent advances in hepatobiliary imaging. However, the most accurate preoperative staging may be possible by integrating preoperative key data. OBJECTIVE: To establish useful strategies for the surgical treatment of gallbladder cancer based on information available before resection. DESIGN: Retrospective review. SETTING: University hospital and tertiary referral cancer center. PATIENTS AND METHODS: From January 1, 1978, through March 31, 2001, 152 patients with gallbladder cancer underwent surgical resection with curative intent. Preoperative diagnoses of the T factor (image-T) and N factor (image-N) in the TNM classification were determined by evaluating all findings of diagnostic imaging, including ultrasonography, enhanced computed tomography, endoscopic ultrasonography, and angiography. The distribution of lymph node metastasis and prognostic factors were also analyzed. RESULTS: The overall diagnostic accuracy for image-T was 52.6% (95% confidence interval, 44.7%-60.6%) and was lower in patients with pT1 and pT2 disease (37.2% and 33.9%, respectively). However, image-T was a significant predictor of lymph node metastasis and patient outcome. Preoperative staging for N was more difficult, with only 24.5% (95% confidence interval, 12.4%-36.5%) of the node-positive patients being correctly diagnosed. An analysis of harvested lymph nodes showed that the cystic, pericholedochal, and posterosuperior peripancreatic nodes were the most prevalent sites of metastasis, and these were considered key nodes for the lymphatic spread of gallbladder cancer. By combining data on image-T and positivity of these key nodes, more accurate TNM staging was possible. Although an extended lymph node dissection provided significantly better survival in patients with pN2 disease, there was no survival advantage to more radical operations, including bile duct resection or pancreaticoduodenectomy. CONCLUSIONS: Although precise preoperative TNM staging for gallbladder carcinoma was difficult, the most accurate staging before resection was possible by integrating image-T classification and data from the intraoperative histopathologic examination of key lymph nodes. Based on this staging, we propose algorithms for the surgical treatment of gallbladder carcinoma.