Liver biopsy by Menghini technique has a relatively low sensitivity and high risk in diagnosing space occupying lesions of the liver. Moreover, any biopsy method except exploratory laparotomy has not been useful in pancreatic lesions. Recently ultrasonically guided percutaneous fine needle aspiration cytodiagnosis is widely used in evaluating space occupying lesions of the liver and deep-seated organ, such as pancrea, because of its high sensitivity, safety and simplicity. Ultrasonically guided percutaneous fine needle aspiration cytodiagnosis was carried out to evaluating its diagnostic performance in 20 patients with space occupying lesions of the liver and in 3 patients with pancreatic lesions who were admitted to the Pusan National University Hospital from Oct. 1985 to Jan. 1986. The results were as follows: 1) Clinically diagnosis before ultrasonically guided percutaneous fine needle aspiration cytodiagnosis were primary hepatoma in 16 patients, liver abscess in 2 patients, hepatic cyst in 2 pateints, pancreatic cancer in 2 patients. 2) The cytodiagnosis in space occupying lesions of liver were as follows: The 14 patients of the 16 patients with clinically primary hepatoma were positive. All of the 2 patients with suspected liver abscess were confirmed. And all of the 2 patients with suspected heaptic cyst were same as clinical diagnosis. 3) The cytodiagnosis of the pancreatic lesions were as follows: Of the two patients with suspected pancreatic cancer one was positive and the negative patient were confirmed pancreatic cancer by the exploratory laparotomy. One patient with clinically pancreatic cyst was revealed as pancreatic cyst by the cytodiagnosis. 4) There was no complication in performing ultrasonically guided percutaneous fine needle aspiration cytodiagnosis.