Purpose: To investigate a robot assistance device for CT-guided percutan liver biopsy. Materials and Methods: The liver of a corpse was equipped with target dummies. Four radiologists used a 16 G needle to perform biopsy of the target region in standard free hand technique and then used a robot system which allowed planning and aligning the trajectory path. Accuracy in terms of needle tip deviation, and time efficiency and radiation exposure in terms of effective dose for the radiologists were measured. Results: For in plane procedures, there was no significant benefit in accuracy when using the robot versus standard technique (4 mm vs. 5.6 mm, p = 0.11);timely effort was worse (443 sec vs. 405 sec, p = 0.64). For angulated punctures, a needle tip of 3.7 mm was measured by using the robotic device (vs. 10.8 mm, p < 0.01);mean biopsy duration was 490 sec (vs. 900 sec, p < 0.01). Mean radiation exposures in freehand technique were 2.4 μSv (in plane procedures) and 10.8 μSv (oblique procedures);the robotic assisted procedures were performed without additional image guidance. Conclusion: The proposed robotic assistance device may be superior for angulated interventions regarding accuracy and timely effort. Furthermore, the zero radiation exposure is a significant benefit for the interventional radiologist.