PURPOSE: Intravenous infusion of albumin has been widely used to relieve severe nephrotic edema in spite of beneficial or harmful effects. The purpose of this study is to examine the harmful effect of albumin on the clinical course of steroid sensitive nephrotic syndrome(SSNS). METHOD: We prospectively randomized the patients with nephrotic syndrome(biopsy proven or clinically compatible to minimal change nephrotic syndrome) into the albumin group(20% albumin 1 g/kg) or control group(5% D/W) between March 1997 and September 1999 at Ewha University Mokdong Hospital. We compared the clinical course of the albumin group(n=13) with the control group(n=13). RESULTS: 1. The duration of steroid therapy until complete remission in the albumin group was significantly longer than the control group(13.7+/-6.4 days vs 7.5+/-2.8 days)(P<0.05). 2, The remission duration to the first relapse was significantly shorter in the albumin group (94+/-63.5 days) than the control group(190+/-106.4 days)(P<0.05). There was no significant difference in the relapse rate within 1 year after complete remission[77% (10/13) vs 46% (6/13)](P>0.05) and the relapse frequency per year(1.9+/-0.8 vs 1.5+/-0.5) between the albumin and control groups. 3. Spot urine protein/creatinine ratio significantly increased in the albumin group at post-albumin 2, 4 days(P<0.05). There was no significant difference in the change of the daily percent weight loss, blood pressure, serum Na, K concentration between the albumin and control groups. CONCLUSION: Albumin infusion in SSNS delayed the response to steroid and shortened the remission duration to the first relapse. Albumin should be carefully used in nephrotic edema.