The authors report the results of 100 liver biopsies with fine needle aspiration performed in patients with primary hepatocellular carcinoma (P.H.C.). The method is simple, quick, without danger and reliable: cytodiagnosis on aspirated material shows typical P.H.C. in 69 p. 100 of cases and probable P.H.C. in an additional 21 p. 100 of cases. Peritoneoscopic or ultrasonic guidance gives even better results.