Background: Hypercalciuria is the most common cause of nephrolithiasis. Many hypercalciuric patients are visited in pediatricians’ offices. Various factors like solutes of water and diet affect the prevalence of hypercalciuria in different areas. So this study was carried out to evaluate the prevalence of hypercalciuria and its related factors in 6-12 years old children in Kashan.

Materials and Methods: This descriptive study was done on 400 children aged 6-12 years old in kashan city and its villages. After determining the sample size and selecting the school that should be studied, investigating teams were instructed about sampling and collecting data. The questionnaire was completed for every child who had not signs of hyperparathyroidism, Cushing syndrome and history of excessive use of vitamin D. Urine samples were collected in plastic sealed labeled containers and were sent to central laboratory of university. Then sodium, creatinin and calcium of samples were tested by flame – Phothometer and RA 1000 apparatus. Children with urine calcium to creatinin ratio more than 0.2 and urine sodium more then 200 meq/lit were known respectively as hypercalcouria and hypernatriuria.

Results: The study was done on 362 out of 400 cases. The prevalence of hypercalciuria was 34.2%, of them 58.1% was male while 47.9% of children without hypercalciuria was male (P<0.09). The prevalence of hypercalciuria at Kashan city and its villages were 33% and 39% respectively. The prevalence of hypernatriuria in children with hypercaliuria was 41.9% but in children without hypercalciuria was 20% (P<0.0001).

Conclusion: The prevalence of hypercalciuria in Kashan city and its villages is high. This is even higher in rural than urban regions. Hypercaciuria prevalence in male is more than female. There is direct relation between prevalence of hypercalciuria and hypernatriuria hence it is recommended another study to compare solutes level of drinking water and excessive use of salt in rural and urban regions of Kashan