Hepatectomy can comprise excision of peripheral tumors as well as major surgeries like trisegmentectomies or central resections. Patients can be healthy, have localized liver disease or possess a cirrhotic liver with high operative risk. The preoperative evaluation of the risk of postoperative liver failure is critical in determining the appropriate surgical procedure. The nature of liver disease, its severity and the operation to be performed should be considered for correct preparation. Liver resection should be evaluated in relation to residual parenchyma, especially in cirrhotic patients, subjects with portal hypertension and when large resections are needed. The surgeon should assess the rationale for the use of hepatic volumetry. Child-Pugh, MELD and retention of indocyanine green are measures for assessing liver function that can be used prior to hepatectomy. Extreme care should be taken regarding the possibility of infectious complications with high morbidity and mortality in the postoperative period. Several centers are developing liver surgery in the world, reducing the number of complications. The development of surgical technique, anesthesia, infectious diseases, oncology, intensive care, possible resection in patients deemed inoperable in the past, will deliver improved results in the future.