Background: Early detection of renal diseases in children can be beneficial for prevention, delaying disease progression, reduction of the number of patients with progressive renal failure. The most common metabolic disorders predisposing renal calculus in children are: hypercalciuria, hyperuricosuria, hyperoxaluria, renal tubular acidosis, and hypocitraturia.Objectives: In this research, we studied the prevalence of urinary infection in healthy elementary school children in Tabriz city and analyzed their urinary profiles.Patients and Methods: This cross-sectional descriptive research was performed in the year 2011, on 312 students who were selected from the students of Tabriz city schools using random cluster sampling. A second morning urine sample was collected in order to analyse the urine and the random levels of calcium, creatinine, uric acid, oxalate, citrate and protein, and the kidneys and urinary tract ultrasonographies were performed.Results: In this research 312 students were studied. Prevalence rate of urinary infection was 3.8 %, 6.3% of girls and 0.7% of boys were positive. The performed ultrasonographies indicated, 0.3% hydronephrosis, 0.3% renal calculus, 0.6% duplication and 5.4% thickened bladder.1.6% of children had Proteinuria. There were 4 cases, 1.28%, of girls’ and 1 case, 0.32%, among boys’ who had hematuria. A total of 8.01% (n=25) hypercalciuria, 7.05% of oxaluria (n=22), 1.28% of hyperuricosuria (n=4) and 13.46% of hypocitraturia (n=42) were observed among the subjects.Conclusions: The results of this research, showed the effectiveness of urinary screening in schools, indicated that early detection of renal diseases in children can be beneficial for prevention, delaying disease progression, reduction of progressive renal failure. These results might be due to geographic differences, diet and genetic background.