Purpose. The purpose Of this study was to compare CT-navigated stereotactic IRE (SIRE) needle placement to non-navigated conventional IRE (CIRE) for percutaneous ablation of liver malignancies. Materials and Methods. A prospective trial including a total of 20 patients was conducted with 10 patients in each arm of the study. IRE procedures were guided using either CT fluoroscopy (CIRE) or a stereotactic planning and navigation system (SIRE). Primary endpoint was procedure time. Secondary endpoints were accuracy of needle placement, technical success rate, complication rate and dose-length product (DLP). Results. A total of 20 IRE procedures were performed to ablate hepatic malignancies (16 HCC, 4 liver metastases), 10 procedures in each arm. Mean time for placement of IRE electrodes in SIRE was significantly shorter with 27 +/- 8 min compared to 87 +/- 30 min for CIRE (p < 0.001). Accuracy of needle placement for SIRE was higher than CIRE (2.2 mm vs. 3.3 mm mean deviation, p < 0.001). The total DLP and the fluoroscopy DLP were significantly lower in SIRE compared to CIRE. Technical success rate and complication rates were equal in both arms. Conclusion. SIRE demonstrated a significant reduction of procedure length and higher accuracy compared to CIRE. Stereotactic navigation has the potential to reduce radiation dose for the patient and the radiologist without increasing the risk of complications or impaired technical success compared to CIRE.