Objective: To determine if reperfusion injury takes place in ovarian tissue following the detorsion of the torsioned ovary. Study design: Fifty-four New Zealand mature nonpregnant female rabbits were divided into six groups. One group served to determine the basal values of thiobarbituric acid reacting substance (TBARS) and another group was sham. In the third and fourth groups, ovarian torsions and subsequent oophorectomy were performed in I and 3 h, respectively. In the fifth and sixth groups, detorsions were carried out after unilateral ovarian torsion lasting I and 3 h. respectively, then oophorectomies of the detorsioned ovaries were performed 2 It after detorsion. The level of TBARS in ovarian tissues was determined in all subjects. Statistical analysis was performed using analysis of variance and Duncan's multiple range test. Differences were considered to be significant if P < 0.05. Results: The levels of TBARS were not different in the basal and sham groups (P > 0.05), while ovarian torsion caused significant increase in TBARS in the ovary (P < 0.05), and detorsion caused a further significant increase in ovarian TBARS (P < 0.05). Conclusion: Reperfusion injury in ovarian tissue, following the detorsion after the torsion of the ovary lasting up to 3 It was demonstrated biochemically in this study. (C) 2003 Elsevier Science Ireland Ltd. All rights reserved.