The detection of blood in a child's urine is alarming and often prompts many laboratory studies. Hematuria is one of the most important signs of renal or bladder disease, but proteinuria often is a more important diagnostic and prognostic finding. The physician should ensure that serious conditions are not overlooked, avoid unnecessary laboratory studies, reassure the family, and provide guidelines for additional studies if there is a change in the child's course. This article provides an approach to the evaluation and management of hematuria in a child. Many tests have been recommended for the child with hematuria, but no consensus exists on a systematic evaluation.