Proteinuria has been shown to be an important and potentially treatable risk factor for graft loss. The aim of this study was to evaluate prevalence, etiology, and outcome of proteinuria during the follow-up of children with renal transplantation. We retrospectively reviewed the files of renal transplanted children between 2006 and 2016 in our center. All patients were interpreted with respect to the demographic data and clinical and laboratory features including information about proteinuria. Chi-square test and Mann-Whitney U test were used for analysis. Fifty-two children were eligible for the study. Proteinuria was observed in 34 (65%) and nephrotic range proteinuria was detected in 5 (9.6%) patients. Etiology of proteinuria could be identified in 21 patients. Acute rejection and uncontrolled hypertension were the most frequent causes of proteinuria. Proteinuria had resolved during the follow-up in 59% of the patients. We found that children with and without proteinuria had similar glomerular filtration rate at the end of 50 months of follow-up period. Proteinuria seems to be a common complication in renal transplant recipients. Graft functions can be preserved by immediate evaluation of increasing proteinuria, and by fixing treatable causes rapidly and efficiently during the follow-up in majority of the patients.