Background and aims Hilar cholangiocarcinoma (HC) is the most common form of extrahepatic cholangiocarcinoma in clinical practice. It is highly malignant and associated with a poor prognosis. Radical resection remains the most effective approach for achieving long-term survival in HC patients. Type Ⅲ and Ⅳ (Bismuth-Corlette classification) HC lesions are complex, with serious surgical difficulty and risk. Surgery by limited hepatectomy carries relatively low risk but may result in a higher rate of positive margins, which may affect prognosis. Conversely, extended hepatectomy may improve radical rates and survival and increase surgical risks. There is yet to be a consensus on the appropriate scope of hepatectomy for type Ⅲ and Ⅳ HC. This study evaluated the efficacy and safety of extended hepatectomy and limited hepatectomy for type Ⅲ and Ⅳ HC by a Meta-analysis to provide evidence-based guidance for clinical decision-making.Methods The clinical control studies comparing extended hepatectomy and limited hepatectomy for type Ⅲ and Ⅳ HC were collected by searching several domestic and foreign literature databases, with a time restriction from inception to November 30, 2022. Two researchers independently screened the literature and extracted data according to inclusion and exclusion criteria, and Meta-analysis was performed using RevMan 5.2 software.Results A total of 11 articles involving 844 patients with type Ⅲ or Ⅳ HC were included in the study, with 423 patients in the extended hepatectomy group and 421 patients in the limited hepatectomy group. The Meta-analysis results showed that compared to the limited hepatectomy group, the extended hepatectomy group had significantly higher radical rates (OR=4.44, 95% CI=2.65-7.45, P<0.000 01) and better clinical prognosis (HR=0.53, 95% CI=0.41-0.68, P<0.000 01). The extended hepatectomy group had a higher incidence of postoperative liver dysfunction (OR=3.00, 95% CI=1.07-8.40, P=0.04), but there were no statistically significant differences in postoperative mortality rate (OR=1.12, 95% CI=0.25-4.99, P=0.88), and incidence rates of overall complications (OR=1.44, 95% CI=0.95-2.18, P=0.09) and other individual complications (bile leakage: OR=1.44, 95% CI=0.68-3.04, P=0.34; abdominal bleeding: OR=0.77, 95% CI=0.29-2.05, P=0.60; abdominal infection: OR=1.36, 95% CI=0.50-3.71, P=0.55). Additionally, the extended hepatectomy group had significantly increased intraoperative blood loss, operative time, and hospitalization duration compared to the limited hepatectomy group (MD=153.48, 95% CI=32.63-274.33, P=0.01; MD=78.19, 95% CI=54.56-101.82, P<0.000 01; MD=2.55, 95% CI=1.61-3.50, P<0.000 01).Conclusion Extended hepatectomy can improve the radical resection rate and significantly enhance the prognosis for stage Ⅲ and Ⅳ HC. Moreover, it does not increase postoperative mortality or overall complication rates. However, an elevated risk of postoperative liver failure is associated with extended hepatectomy. Given the limitations of this study, further prospective randomized controlled trials are still needed to provide additional verification.