The state of art of ultrasound technology has reached a fundamental role, due to the color Doppler methodology, in the study and diagnosis of scrotal pathologies, especially those related to vascular, neopalstic and inflammatory disease. The varicocele is one of the most frequent causes of male infertility, even in the sub-clinical forms. The role of echo-Doppler is to achieve a diagnostic conclusion in the sub-clinical forms, to suggest the type and value of clinical varicocele, to give morphological and structural informations of the scrotal contents, useful for the therapeutic choice and follow-up, to evaluate the therapy success, the eventual persistency or recurrence. Moreover, in the undescended testis the ultrasound technique represents the best non-invasive diagnostic means. This technique allows to disclose the undescended testis, up to the supra-lateral angle of bladder, to evaluate it in both the volumetric and echostructural aspect and to correlate those data to that of contra-lateral normosited testis and to the per age standards. On the other hand, echography results in less utility in the abdominal undescended testis.