BACKGROUND: Improvements in the understanding of intrahepatic anatomy and radiographic technology have facilitated a segment-oriented approach to liver resection. This approach involves the resection of isolated anatomic segments or sectors of the liver as dictated by the extent of the intrahepatic pathology. Segment-oriented resection allows maximal conservation of normal liver parenchyma while clearing tumor. This report describes the technical features and the results of a prospective evaluation of segmental and sectoral resections in the treatment of malignant hepatic neoplasms. STUDY DESIGN: Patients with malignant hepatic neoplasms that were treated with a segment-oriented hepatic resection were identified from a prospective clinical data base. After undergoing segment-oriented liver resection, the patients were followed at regular intervals. Recurrent disease was the end point of the study. Followup is reported at a median of 12 months. This review outlines the technique of resection, intraoperative events, operating time, blood loss, and the ability to obtain negative resection margins. RESULTS: During the 5-year period between July 1992 and July 1997, 400 patients underwent liver resection for metastatic neoplasms and hepatocellular carcinoma (HCC). During this period, 79 patients (20%) were treated with a segment-oriented resection. These patients represent the study group for this report. The overall mortality rate was 2.5%; all postoperative deaths occurred in patients with HCC and cirrhosis. Overall morbidity was 26%. The median hospital stay was 8 days. Mean transfusion requirements were 1.0 +/- 0.3 U of packed red blood cells. Patients with HCC showed a greater transfusion requirement than did patients without HCC: 2.7 +/- 1.2 U versus 0.6 +/- 0.2 U (p < 0.05). Of the patients without HCC, 17% required transfusion. During the 12-month median followup period, the overall disease recurrence rate was 23%. Disease recurred at the hepatic-resection margin in 2.5% of the patients. CONCLUSIONS: Segmental resection is a safe technique that allows complete resection of liver tumors with preservation of normal liver parenchyma. Segmental resection is particularly useful for patients with HCC and patients undergoing repeat liver resections or bilobar resections.