In 122 children (ages, newborn to 17 years) without urinary tract disease, 244 kidneys were examined sonographically. Renal length and volume were measured and correlated with age, body weight, height, and total body surface area, permitting preparation of nomograms with predicted means and 95% prediction intervals. Also evaluated were renal parenchymal echogenicity, medullary pyramids, and central sinus echoes, and the appearance of each was correlated with age.