OBJECTIVE To investigate the impact of garlic extract (GE), which is known for its antioxidant activity, on a testicular torsion/detorsion model in animals and to help understand how to prevent both ischemic and reperfusion injuries after testicular torsion and detorsion. METHODS Six groups of rats (n=7 in each group) were used. The animals in the control group (Group I) did not receive any treatment. The animals in the sham group (Group II) underwent scrotal incision and testicular fixation only. The animals in Groups III-VI underwent 720 degrees of left testicular torsion for 2 h; subsequent detorsion was performed for 2h in Groups IV and VI only. Animals in Groups V and VI were treated exactly the same as those in Groups III and IV, respectively except that they were pretreated with oral GE for 5 days at a dosage of 5 ml/kg. Both testicles in all rats were removed and tissue malondialdehyde (MDA) levels and enzymatic activities of xanthine oxidase (XO) were studied, in addition to a histological evaluation after hematoxylin-eosin staining. RESULTS Testicular MDA levels and XO activities were higher in Group III compared to Group II (p<0.05). Pretreatment with GE prevented these increases. Detorsion caused more damage and resulted in a further increase in MDA levels but MDA levels were not increased in animals pretreated with GE. Histologically, torsion caused some separation between germinative cells in the seminiferous tubules, which became much more prominent in Group IV and was attenuated by GE pretreatment. There were no significant changes in any of the above-mentioned enzymatic activities or histopathologic changes in the contralateral testicle in any of the groups. CONCLUSIONS We believe that both testicular torsion and detorsion result in testicular tissue damage by means of lipid peroxidation, which is evident by an increase in the tissue levels of MDA. Dietary supplementation with GE seems to attenuate the generation of toxic free radicals, as evidenced indirectly by low tissue MDA levels.