Radiologically guided interventional procedures in the liver have continually increased, in number and variety, over the years. Factors promoting these advances include new technology, innovative ideas, and growing acceptance by clinicians and patients. Percutaneous biopsy and drainage procedures are firmly established techniques with low complication rates. Ablation by injected substances is useful for treating certain tumor types. The most exciting development is the introduction of percutaneous thermal techniques for tumor ablation. Although more experience is needed to optimize the use of focal thermal ablation, early results seem promising.