Background:Idiopathic hypercalciuria is an important cause of symptoms related to the urinary system. The urinary excretion of high sodium and low potassium is a risk factor for hypercalciuria and urolithiasis. The aim of this study was to compare the urinary excretion of sodium and potassium by children older than two with idiopathic hypercalciuria and healthy control children in Bandar-Abbas, Iran.Methods:This case control study was conducted during 2012 and 2013 in Bandar-Abbas, a city in southern Iran. The urinary excretion of sodium and potassium by 50 children with idiopathic hypercalciuria who were older than two was compared with that of 62 healthy children. IBM SPSS Statistics 21 software was used to analyze the data, and P < 0.05 was considered to be significant.Results:Fifty children with idiopathic hypercalciuria (21 males and 29 females) were compared with 62 healthy children (19 males and 43 females). The results of the study indicated that there were no significant differences in the mean sodium and potassium levels in the urine of the two groups of children (P = 0.401 and P = 0.479, respectively.)Conclusion:The study showed no significant differences in the excretion of sodium and potassium in the urine of children with idiopathic hypercalciuria and that of healthy children in Bandar-Abbas. This finding was inconsistent with the results of similar studies conducted earlier. Therefore, more studies are needed on populations in different areas with various climates and difference races.