The present study assessed the benefits of 3-D reconstruction of spiral computerized tomography (CT) scans for the diagnosis of and surgical guidance to large liver tumors or tumors at the hepatic hilum. We retrospectively analyzed the cases of 18 children with large liver tumors or with tumors at the hepatic hilum treated in past 5 years. The ages ranged from 45 days to 14 years. Ten cases were examined using the three-dimensional reconstruction using 64 slice spiral CT and eight patients underwent conventional CT or conventional enhanced CT scanning. In 16 cases, the volume of tissue removed exceeded one-third the entire volume of the liver (considered "large" tumors). The largest tumor removed weighed 4.8 kg. In two cases, the excised tissue represented less than one-third of the total liver volume, but in these cases the location of the tumor was considered "complex" due to the proximity to major hepatic vessels. Seven tumors were located in the right lobe, three in the left lateral segment, three in medial segment, three extended beyond the right lobe and two extended beyond the left lateral segment. Pathological diagnoses included hepatoblastoma (n = 9), hepatocellular carcinoma (n = 2), mesenchymal hamartoma (n = 4), teratoma (n = 1) and adenoma (n = 2). The 3-D reconstructed images could be rotated to view the image from several sides, were semitransparent and allowed for the measurement of tumor size and determination of spatial relation to blood vessels. All 18 children had curative resections as indicated by "tumor-free" microscopic margins. No major intra- or postoperative complications were encountered. Three-dimensional CT imaging can provide high quality images of the tumors and location of the tumor relative to vital hepatic blood vessels. This technique offers a kind of comparatively accurate method compared with traditional imaging techniques, it could help the surgeon identify the tumor borders accurately and devise a comparative safe surgical strategy. With its help the surgeon could identify vital hepatic blood vessels before operation, so they can avoid massive hemorrhaging and avoid massive hemorrhaging during operation. This technique should be more widely applied in the resection of large or complex liver tumors.