Percutaneous treatment of transitional cell carcinoma of the renal pelvis in 4 patients is reported. The presenting symptom was hematuria in 2 patients, while in 2 diagnosis was made by chance at excretory urography. Endoscopic removal of the tumor was not possible in the 2 patients who underwent transurethral ureteroscopy due to the location of the lesion. Percutaneous electroresection of the tumor was performed after puncture of an inferior (3 patients) or middle (1) calix and dilation of the nephrostomy tract up to 30F. Pathological findings revealed a grade 1 papillary carcinoma in 3 patients and a well differentiated inverted papilloma in 1. A single-J ureteral catheter was left in place after the procedure. Cytological, radiographic and endoscopic studies were negative 11, 13, 18 and 24 months after the treatment, respectively. We believe that the percutaneous approach is a feasible option in cases of small, single, low grade lesions not removable via ureteroscopy, particularly in patients at high surgical risk.