Mammalian testes are highly sensitive to oxidative free radical damage. Acute scrotum is a clinical syndrome mainly caused by torsion of the spermatic cord that constitutes a surgical emergence affecting newborns, children and adolescents. This syndrome often leads to infertility of the ipsilateral (torted) and contralateral (not torted) testis, an outcome that makes surgical intervention mandatory. There is a controversy involving the effects of ischemia and reperfusion on ipsilateral and contralateral testes after unilateral torsion and detorsion of the spermatic cord. Conflicting reports have led to two distinct and opposite recommendations regarding surgical intervention: detortion and preservation of the ipsilateral testis, or ipsilateral orchiectomy to preserve contralateral fertility. Early detortion surgery in humans preserves fertility, but after prolonged torsion periods followed by preservation of the ipsilateral fertility of both testis is jeopardized. Lowered contralateral blood flow after unilateral testicular torsion is associated with reactive oxygen species (ROS) overgeneration and therefore with the corresponding tissue damage. Reperfusion time appears to be determinant of contralateral testes damage due to the consequent oxidative insult that accompanies the rise in ROS following ischemia-reperfusion. Nevertheless, more investigations on the molecular mechanisms and the antioxidant status in testis are necessary to ascertain the contribution of ROS to the tissue damage produced by spermatic cord torsion in experimental animals and humans.