Hematuria is one of the most common urinary abnormalities found in children. When hypercalciuria was identified as a potential etiology of painless hematuria, many questions arose concerning the general importance of this observation. Subsequently, increased uric acid excretion also has been purported to cause hematuria in children. This review traces the history of these observations and describes the clinical characteristics of the clinical syndrome of hematuria associated with hypercalciuria and hyperuricosuria. Diagnostic criteria of excessive urinary excretion of calcium and uric acid are reviewed; differences in urinary calcium and uric acid excretion between infants and older children are emphasized. Aside from urolithiasis, few long-term consequences from hypercalciuria or hyperuricosuria have been identified, although some debate exists concerning the effect of chronic hypercalciuria upon bone mineralization.