The paper presents the principles of performing proper ultrasound examinations of the urinary tract. The following are discussed: preparation of patients, type of optimal apparatus, technique of examination and conditions which its description should fulfill. Urinary track examination in adults and in children constitutes an integral part of each abdominal examination. Such examinations should be performed with fasting patients or several hours after the last meal, with filled urinary bladder. Apparatus: Ultrasound examinations in children and infants are performed using transducers with the frequency of 5.0–9.0 MHz and in adults – with the frequency of 2.0–6.0 MHz. Doppler options are desirable since they improve diagnostic capacity of sonography in terms of differentiation between renal focal lesions. Scanning technique: Renal examinations are performed with the patients in the supine position. The right kidney is examined in the right hypochondriac region using the liver as the ultrasound “window.” The left kidney is examined in the left hypochondriac region, preferably in the posterior axillary line. Ultrasound examinations of the upper segment of the ureters are performed after renal examination when the pelvicalyceal system is dilated. A condition necessary for a proper examination of the perivesical portion of the ureter is full urinary bladder. The scans of the urinary bladder are performed in transverse, longitudinal and oblique planes when the bladder is filled. Description of the examination: The description should include patient’s personal details, details of the referring unit, of the unit in which the examination is performed, examining physician’s details, type of ultrasound apparatus and transducers as well as the description proper.