The purpose of this article is to retrospectively evaluate the long-term outcome of patients treated with percutaneous thermoablation for renal cell carcinomas that have arisen in kidney grafts. Between April 2008 and February 2011, we treated 3 patients with renal cell carcinoma on a transplanted kidney: 2 cases were treated with high-intensity focused ultrasonography and 1 patient with radio frequency ablation. Postprocedural ultrasonography did not reveal any complications, and contrast-enhanced ultrasonography showed an avascular area in the treated nodules. None of the patients had recurrent tumors during a long-term clinical and radiologic follow-up (81, 73, and 43 months, respectively).