Hematuria and proteinuria are often the first signs of potentially severe kidney diseases. Investigations of a child with proteinuria +/- hematuria should start at the primary care physician office, and will permit to rapidly identify the most serious kidney diseases, such as the glomerulonephritis, but also to avoid excessive and costly investigations in patients with a benign condition such as orthostatic proteinuria. Isolated microscopic hematuria is also relatively frequently found during routine pediatric office visit. Secondary to a glomerulonephritis, it is often associated with proteinuria. Urologic causes should be excluded in case of isolated microscopic or macroscopic hematuria.