Submucosal injection of Teflon for treatment of vesicoureteral reflux (the sting of O'Donnell) was used in 43 patients (66 ureters-21 bilateral cases). 14 patients were on dialysis and reflux was diagnosed at medical evaluation during pretransplantation work-up; correction of reflux was indicated as a preparation for renal transplantation. In another group of 24 patients with normal renal function reflux appeared as a simple congenital abnormality. 5 patients had reflux secondary to TUR or ureteral reimplantation. The procedure was performed under general or epidural anesthesia. Ultrasound examination of kidneys was performed 24 hours after the procedure, cystography and UIV was performed after 30, 100 days and one year. No ureteral obstruction were observed. In the first group of patients (on dialysis) correction of reflux was effective in 40% of cases. In the second group (congenital vesicoureteral reflux) correction was observed in 85% of cases (30/35 controlled cases). In the third group correction of reflux was observed in 83% of cases (5/6). Results in the first group of patients may be due to technical difficulties while injecting of Teflon in small, thickened sclerotic bladders. Though longterm results are still to be evaluated. The sting may be beneficial in patients on dialysis waiting for a renal transplant as it obviates the need for bilateral nephrectomy. In simple congenital reflux short and middle term results are excellent.