The ultrasound of prostate and seminal vesicles provides several morphologic and functional information in a non-invasive and fast way. The approach can be trans-abdominal or trans-rectal, with the help of different kinds of probes. The trans-rectal approach is the most frequently used, especially when a precise and rapid measure of the dimensions of the prostate is necessary, together with the evaluation of the presence of anatomical anomalies (third lobe, calcification, embryologic residues). The study of the seminal vesicles is preferable with a trans-rectal approach, especially in case of suspicious anomalies of the seminal tract or inflammations.