Testicular tumors in infants are uncommon; yolk sac tumor is the most prevalent germ cell malignancy. When the patient is diagnosed with this tumor before two years of age and the alpha-fetoprotein level returns to normal following the surgical removal of the tumor, the prognosis is improved. Scintigraphy is performed to show increased flow and heterogeneous tracer distribution. The authors present a case of an infant who underwent testicular scintigraphy for suspected acute scrotum. The study was performed to differentiate between torsion and epididymo-orchitis. Testicular scintigraphy was consistent with an inflammatory process; however, the patient did not develop the clinical signs of epididymoorchitis. On histology, a yolk sac tumor was identified. Thus, when the clinical presentation of a swollen scrotum is uncharacteristic of infection, scintigraphy can be misleading and testicular tumor should be considered.