In brief: Boxers, baseball players, and some other athletes are sometimes at risk of injury to the genitalia. For some injuries, such as testicular rupture or acute torsion, early surgery increases the likelihood of preserving function. Other injuries are more appropriately treated conservatively. When a patient has severe pain, physical examination of the scrotum can be difficult, and information obtained with ultrasound and radionuclide scintigraphy can help in the diagnosis and treatment. The authors compare normal findings with those indicating the presence of hematocele, intratesticular hemorrhage, testicular fracture, torsion, and epididymo-orchitis.