Eighteen steroid-responsive children with nephrotic syndrome were vaccinated with pneumococcal vaccine (PNEUMO-23) in order to investigate the effectiveness and necessity of this vaccine and they were followed up for three years. Twenty steroid-responsive children with nephrotic syndrome were also followed up for the same period without vaccination as a control group. Relaps rate in the study group after vaccination was 1 / 19.1 patient months, while it was 1/16 patient months in the control group, and a significant difference was found between them (p < 0.05). Infection rate oj relapses was also significantly lower in the study group (62.5 %) than the control group (55.5 %) (p < 0.01). Thirteen patients whose follow-up period was more than one year before vaccination showed a significant decrease in relaps rate after vaccination which was found to be 1 / 13.3 ± 1 / 57.14 patient months (p < 0.01). Infection rates of relapses in the study group also decreased after vaccination (p < 0.001). This study showed that pneumococcal vaccination decreased the frequency of relapses and infection rate in children with nephrotic syndrome and it is concluded that routine vaccination of these patients would be of benefit.