Retrospective evaluation of 510 percutaneous CT-guided biopsies of the liver mainly fine-needle aspiration biopsies for cytology (89% of cases), yielded an overall accuracy rate of 92% and a sensitivity of 94%. The relatively high percentage of false-positive diagnoses (7% of all benign tumors) may be reduced by more consistent consideration of possible errors in cytology and a more consistent use of large bore biopsies.