A 5-year-old boy was investigated after an episode of gross hematuria of non-glomerular origin and was found to have idiopathic hypercalciuria. Despite normalization of calciuria he had recurrent attacks of gross hematuria. Since SDS-PAGE analysis of urinary proteins indicated a glomerular origin of hematuria, a renal biopsy was performed and revealed IgA nephropathy. We believe that association of hypercalciuria and IgA nephropathy is by chance, since both are frequently found in children with hematuria. Also, we recommend all children with well-controlled hypercalciuria who experience further attacks of gross hematuria be evaluated for glomerular disease.