Ultrasound is a vital adjunct to clinical examination in diagnosing scrotal disease, as a number of different processes may present similarly. Potential applications range from the acute emergency to long-term screening as well as cases in which a distinct scrotal abnormality may or may not be palpable. Differentiating acute epididymitis/epididymoorchitis from testicular torsion is possible sonographically, thereby guiding appropriate medical or surgical management. Distinguishing between cystic, solid, or complex scrotal masses is readily performed with this modality. It clearly depicts simple versus complex hydroceles and determines the presence of underlying testicular or epididymal disease. Not only is ultrasound the best imaging modality for longitudinal screening in patients (testicular microlithiasis, cryptorchidism) at risk for testicular tumors, it also provides valuable information in the infertile male by documenting the presence or absence of a varicocele.