One hundred and eighteen patients with various hepatic tumors proved by laparotomy have been analyzed for accuracy and for pitfalls of preoperative studies, namely, physical examination, celiac and superior mesenteric angiography and liver scan. Angiography is correct in detecting a hepatic tumor in 93 per cent and scan, in 87 per cent, overall. When angiography and scan are combined, tumors are detected in 97 per cent of patients. As for specific location and extent of the hepatic tumor to determine its resectability, angiography is correct in 75 and scan in 62 per cent, over-all. Eleven of 39 resectable tumors were deemed nonresectable in preoperative studies. Although angiography and scan are the best available means of diagnosing hepatic tumors, presently, true resectabilty of hepatic tumors can be determined only be exploratory examination.