Percutaneous thermal ablation is increasingly being studied in the treatment of renal tumors. Because radiofrequency ablation is a minimally invasive and nephron-sparing procedure, it is ideally suited for patients with a single kidney, multiple tumors, or contraindications to conventional surgery. We report on a patient with recurrent renal cell carcinoma in a transplanted kidney that was successfully treated with percutaneous ultrasound-guided radiofrequency ablation.