Computed tomographic [CT] guided fine needle aspiration biopsy of 25 consecutive patients with a variety of confirmed malignant abdominal and pelvic neoplasms resulted in a 100% yield of positive tissue diagnoses without significant complications. The principal advantage of CT guidance is the continuous direct observation of the needle tip position in relation to the target volume. Simultaneous insertion of 2 fine caliber biopsy needles (tandem needle maneuver) is a new technique developed for rapid, accurate needle repositioning for repeated aspiration attempts. CT guidance, multiple aspirates with the fine needle and the tandem needle maneuver for precise localization all contribute to a high rate of tissue diagnoses. Because CT guidance permits more precise sampling of smaller, deeper tumors than other procedures including ultrasonic biopsy transducer systems, it is preferred for percutaneous tissue sampling of abdominal neoplasms. A large proportion of symptomatic abdominal malignancies which can be diagnosed by CT apparently are amenable to successful percutaneous biopsy by this technique.