While studies show that prolonged initial prednisone therapy reduces the frequency of relapses in nephrotic syndrome, they lack power and have risk of bias. In order to examine the effect of prolonged therapy on frequency of relapses, we conducted a blinded, 1:1 randomized, placebo-controlled trial in 5 academic hospitals in India on 181 patients, 1-12 years old, with a first episode of steroid-sensitive nephrotic syndrome. Following 12 weeks of standard therapy, in random order, 92 patients received tapering prednisolone while 89 received matching-placebo on alternate days for the next 12 weeks. On intention-to-treat analyses, primary outcome of number of relapses at 1 year was 1.26 in the 6-month group and 1.54 in the 3-month group (difference -0.28; 95% confidence interval (CI) -0.75, 0.19). Relative relapse rate for 6- vs. 3-month therapy, adjusted for gender, age, and time to initial remission, was 0.70 (95% CI 0.47-1.10). Similar proportions of patients had sustained remission, frequent relapses, and adverse effects due to steroids. Adjusted hazard ratios for first relapse and frequent relapses with prolonged therapy were 0.57 (95% CI, 0.36-1.07) and 1.01 (95% CI, 0.61-1.67), respectively. Thus, extending initial prednisolone treatment from 3 to 6 months does not influence the course of illness in children with nephrotic syndrome. These findings have implications for guiding the duration of therapy of nephrotic syndrome.