Percutaneous radiofrequency ablation is a minimally invasive treatment that is currently used to treat renal tumors. Despite its minimally invasive nature, potential serious complications can occur. We report the second case of ureteropelvic junction obstruction after radiofrequency ablation that resulted in nephrectomy. The use of radiofrequency ablation should be considered with caution, particularly when tumors are centrally located or abut the renal pelvis. Additional data are needed to better define the indications and contraindications to minimally invasive ablative technologies when used in the clinical setting.