Kidney disease is a common disease among the people of Indonesia. The leaves from angsana tree (Pterocarpus indicus Willd.) is an alternative used empirically by Indonesian people to treat and prevent kidney diseases. The aim of this study was to demonstrate the scientific nephroprotective effect of water-boiled angsana leaves evaluated from urine volume, urinary sodium and potassium levels. Thirty white male Sprague-Dawley rats were divided into five treatment groups; group 1 as normal control group, group 2 as induction group, and group 3 to 5 as dose groups. Doses for angsana leaves were variated to 28,8 mg/kg bw; 57,6 mg/kg bw; and 115,2 mg/kg bw which were given orally for 21 days as single doses. The antibiotic gentamicin is used as a nephrotoxic agent at 80 mg/kg given by intraperitoneal injection from day 15to 21. Nephroprotective effects were observed from levels of urinary output, urinary sodium, and urinary potassium. Obtained results show the group given the highest dose (115,2 mg/kg bw) resulted in decreased sodium levels and increased levels of urinary potassium as well as having a significant difference (p<0,05) with the induction group. Observed 24-hour urine volume, however, did not show significant signs for nephroprotective effects. It can be concluded that the leaves of angsana at the dose 115,2 mg/kg bw/day has potential nephroprotective properties.