Objective To investigate the effect of nifedipine on testicular torsion-detorsion injury. Materials and Methods Twenty-four adult male Sprague-Dawley rats were randomly divided into 3 groups, each containing 8 rats. Rats in the control group underwent a sham operation of the left testis. In the torsion-detorsion (T/D) group, the left testis was twisted at 720° for 3 hours. After 3 hours of reperfusion, at the end of the experiment, the testes were removed. Rats in the treatment group received the same surgical procedure as the T/D group, but nifedipine was administered intraperitoneally (100 μg/kg) 30 minutes before the time of detorsion. Results Unilateral testicular torsion-detorsion caused a significant increase in the malondialdehyde level and apoptosis and caused significant decreases in superoxide dismutase and glutathione peroxidase activities in ipsilateral testes. The rats treated with nifedipine had a significant decrease in malondialdehyde level and apoptosis and had significant increases in superoxide dismutase and glutathione peroxidase activities in ipsilateral testes compared with those of the T/D group. Conclusion These results suggest that biochemical and histological torsion-detorsion injury occurs in the ipsilateral testes after a 3-hour torsion and 3-hour detorsion and that administration of nifedipine before detorsion prevents ischemia/reperfusion cellular damage in the testicular tissue.