The use of 3D ultrasonography in urology is a recent acquisition. The versatility of the 3D US device, as well as the huge potential offered by image acquisition on a third scanning plane, makes the method extremely interesting for diagnostic purposes to make in-depth studies of urological diseases that can be studied by ultrasonography (Giubilei G et al., Int J Urol 12:936–938, 2005; Martino P et al., J Urol 164:456, 2000; Walter WJ 3rd et al., Accuracy evaluation of a 3D ultrasound-guided biopsy system. NIH 8671, 2013; Silva-Ramos M et al., ISRN Urol 2012:158437, 2012; Martino P et al., Arch Ital Urol Androl LXXII:163–167, 2000). 3D US devices are designed to acquire a large number of images for display on the monitor, showing the sagittal, transverse, and coronal planes simultaneously. The organ that has been most closely studied in urology with the 3D US device is surely the prostate. Owing to its particular anatomical position, the prostate gland is ideally suited to US studies of normal or pathological characteristics. The 3D US provides important information about organ morphology and volumetrics, as well as playing a promising role in the diagnostic workup of prostatic carcinoma. A 3D Doppler is numbered among the various fields of application of the method because it allows a three-dimensional view of the vascular tree both in the kidney (normal, pathological, transplanted) and in the external genitals, enabling close study of any vascular disorders present.