Thanks to the wide geographical diffusion, low cost and lack of ionizing radiation, ultrasound is now the most widely used imaging technique in clinical practice, second only to chest radiography. Recent technological innovations and introduction of ultrasound contrast agents, further expanded the fields of application of ultrasound, guarantying for the future to this technique an important role in imaging of the urinary tract. The nephrologist must be able to exploit the potential offered by technological innovations in ultrasound imaging for the study of the kidney. The proper management of equipment, in fact, allows to obtain ultrasound images in gray scale of the highest quality, to optimize the diagnostic accuracy of Doppler techniques and take full advantage of the tools offered by means of ultrasound contrast agents.