A 62-year-old man with renal cell carcinoma in the solitary kidney after right nephrectomy underwent CT-guided radiofrequency ablation. The tumor, which was located in the dorsal part of the lower aspect of the kidney, was exophytic and measured 2 cm in diameter. A 17-gauge, internally cooled radiofrequency needle electrode was placed percutaneously into the center of the lesion. Dynamic CT 6 days after the first ablation showed band-like residual lesion along the intact renal parenchyma. A second ablation was performed for the residual lesion. CT both 1 and 3 months after the second procedure demonstrated complete ablation with the normal renal parenchyma maintained.