Differentiation of renal(RH) and non-renal(NRH) hematuria is important in the diagnosis and treatment of the patients with hematuria. Recently, urine RBC immunoperoxidase(IPx) staining method was developed, but there was no report on the usefulness of IPx in Korea. We validated the usefulness of IPx by comparing with the PCM. Both PCM and IPx were performed at the same time in 26 patients with RH confirmed by renal biopsy and 23 patients with NRH confirmed by radiologic and/or pathologic studies who were admitted to Chungbuk National University Hospital from January 1996 to December 1996. The age of RH and NRH group were 36.6+/-15.0 and 56.5+/-22.2 years. 35.7+/-30.4% of urine RBC were stained by IPx in RH group and only 1.6+/-4.4% were stained in NRH group(P<0.001). 23.4+/-29.9% of urine RBC by PCM were counted as dysmorphic RBC in RH group and 5.7+/-13.6% were counted in NRH group(P<0.05). At the cut-off value of 20%, the sensitivity and specificity of IPx were 57.7% and 100%. At the cut-off value of 30%, those of PCM were 30.9% and 95.7%, respectively. When comparing overall test performance by calculating AUCs of ROC(receiver operating characteristics) curve, IPx was better than PCM. IPx was better than PCM in localizing the origin of hematuria. The NRH might be excluded when IPx(+) cells are more than 20% of total urine RBC.