Renal cell carcinoma (RCC) accounts for approximately 3% of malignancies and 80-90% of malignant neoplasms of the kidney in adults. The incidence of RCC continues to increase. Due to widespread use of cross-sectional imaging modalities, small and localized tumors are now being detected at an early stage. Percutaneous image-guided thermal ablation for early stage RCC is a minimally invasive technique that has rapidly gained acceptance as an alternative to surgery. This technique provides a low incidence of complications, shorter operative-time, protection of renal function, lack of inherent surgery risks, and shorter hospital stay while remaining an effective method of adequate destruction of tumor tissue. The current ablation techniques include cryoablation, radiofrequency ablation (RFA), high-intensity focused ultrasound and microwave ablation (MWA). Image-guided percutaneous MWA has been effectively and safely applied to treat renal tumors in select patients. In contrast to RFA, percutaneous MWA has the advantage of providing higher temperatures in a shorter time. Thus, MWA allows a more uniform tumor necrosis than RFA. The indications for renal MWA include T1a or T1b tumors (<= 4 cm or 4-7 cm), patients with multiple comorbidities who are poor candidates for resection, a tumor in a solitary kidney, bilateral renal tumors, hereditary renal tumors, renal insufficiency, von Hippel-Lindau syndrome, and palliative treatment of hematuria. In conclusion, percutaneous MWA appears to be a safe and effective treatment option for T1a and T1b tumors and for patients who are poor surgical candidates.