The urinalysis is one of the most commonly performed tests in pediatrics, and whether expected or incidental, abnormal findings are common. Understanding the strengths and limitations of the urinalysis allows one to maximize its use as a screening tool while avoiding expensive and unnecessary evaluations. This article reviews the significance of abnormal results on urine dipstick testing and urine microscopy. Causes of false positive and false negative results are summarized. Initial diagnostic considerations of abnormal urinalysis findings are provided where appropriate.