We studied retrospectively the clinical course of 32 steroid sensitive nephrotic children with frequent relapses with or without steroid dependency associated with minimal glomerular lesions. Six hundred twenty-seven relapses were traced during a mean observation period of 7 years per patient. The median period between the beginning of significant proteinuria and the start of prednisone therapy was 5 days (range 0-194 days). At least one spontaneous remission occurred in 10 of the 15 frequent relapsers and in 11 of the 17 steroid dependent patients. Twenty-three percent of the relapses in frequent relapsers and 10% of the relapses in steroid dependent patients remitted spontaneously. The disappearance of proteinuria was documented in 79% of these relapses between day 4 and day 14 after onset. A delay of up to 10 days in starting prednisone therapy did not influence the further course of this or the subsequent relapse. Our results suggest that this delay is justified in the absence of progressive clinical signs and may, by the occurrence of spontaneous remissions, contribute to reduce the total amount of steroids needed.