Testicular torsion is described as the twisting of the spermatic cord resulting in acute pain and ischemia. This has a tendency to occur more frequently during adolescence and its cause is unknown. The most common signs and symptoms include red, swollen scrotum and acutely painful testicle, often in the absence of trauma. Nausea and vomiting are common. The most common conditions in the differential diagnosis include epididymitis, strangulated inguinal hernia, traumatic hematoma, testicular tumor, or testicular fracture. Physical examination techniques such as scrotal elevation can be helpful in differentiating between epididymitis and testicular torsion, but emergent imaging with Doppler ultrasound seems to be the most helpful in confirming the diagnosis. Radionuclide testicular scintigraphy with 99mTc is helpful when past the acute phase (the first 12 hours) and vascular compromise has prolonged. The clinician may attempt to manually reduce the torsion, but many need to be immediately referred to a urologist for a surgical exploration. Long-term prognosis for a functional, nonatrophied testicle is improved the sooner the torsion is diagnosed and treated.