The technique of renal biopsy includes the preparation of the patient, the localization of the kidneys, the biopsy itself and the postbiopsy care of the patient. A review of the literature and a survey of pediatric nephrologists practicing in the New York metropolitan area and in Philadelphia was used to determine what those techniques were. In preparation for biopsy, bleeding disorders are excluded and corrected if present. In units that localize the kidney by anatomical landmarks, a sonogram is performed at some earlier time to determine that the patient has two kidneys in the usual location. After sedation, patients are placed in the prone position, with a bolster under the abdomen. Sonography is the most commonly used localization method. This is followed by probing to confirm localization and depth. The Tru-Cut needle and the Franklin Vim Silverman needles are the two most commonly used. All nephrologists in the New York area then have the specimen examined to ensure adequacy of sampling. Postbiopsy care includes observation of vital signs, bed rest overnight and some limitation of activity for 2 days to 2 weeks subsequently. In the biopsy of renal allografts, palpation achieves adequate localization. The technique is otherwise the same as for the biopsy of native kidneys.