Percutaneous fine needle biopsy guided by computed tomography is now a well established method in most university radiological departments. Positive results are obtained in some 80% of cases. With this tehcnique most abdominal and pelvic structures can be reached without danger for the patient under local anesthesia, even when the fine needle passes through the gastric or bowel walls. In some instances the technique can also be employed for biopsy of pulmonary and mediastinal lesions.