Due to the progress in the management of liver cancer, the resection's limits have been pushed back and the concept of complex hepatectomy has become relevant. We identify five major factors affecting the complexity of hepatectomies. 3 with a direct effect on the peri-operative complications: 1) residual liver volume and quality; 2) the need of a vascular or biliary reconstruction and 3) the presence of co-morbidities. In addition to these factors, 2 major elements affect the long-term survival: 4) the extent of the tumoral disease and 5) the anatomical proximity of tumoral lesions to vascular or biliary structures. All these factors impact the ultimate outcome, requiring careful planning, operation and follow-up. This review summarizes the state of the art approach to complex hepatectomies.