Background/Aim: Ureteric obstructions are one of the common urological surgical problems encountered in the pediatric age group. Today the diagnosis and follow-up of these cases are mainly done with radionucleid studies. Nuclear medicine studies may not be applicable in various conditions such as, renal insufficiency or in renal units that are decompressed in the postoperative period and early function evaluation is necessary. In these conditions, a diuretic enhanced nephrostometry test performed through a nephrostomy tube placed during surgery, maybe helpful in identifying early postoperative obstruction. In this study we aim to evaluate dthe iuretic enhanced nephrostomy test, which was applied to 33 renal units. Methods: In renal units which nephrostomy tubes were inserted during surgery, the mean basal pressure, peak pressure and the pressure 20 min. after diuretic injection were evaluated. Results: In 28 renal units that surgery was considered to be successful based on clinical and radiological findings and diuretic renograms; the mean basal pressure was 10 cmH2O, mean peak pressure was 20 cmH2O and the mean pressure 20 min. after diuretic injection was 14 cmH2O. Among the 5 renal units that surgery was noted to be unsuccessful, the mean basal pressure was 19 cmH2O, peak pressure was 49 cmH2O and the pressure 20 min. after diuretic injection was 27 cmH2O. Comparison of the results of two groups were found to be statistically significant (p<0.01). Conclusion: Diuretic enhanced nephrostometry (modified Whitaker test), is found to be a simple and easily applicable test in assessing the success of surgery in renal units that carry the risk of postoperative obstruction. The technique carries the advantage of defining ureteric obstructions in cases that radionucleid studies cannot be used.