Objective : The aim of this study was to investigate the effects of hyperbaric oxygen therapy on experimental ovarian ischemia and reperfusion injury in rats. Material and methods : In this study, 27 Sprague Dawley rats were randomly grouped as 6 in the Sham group and 7 in the other groups. Torsion (T), Torsion and Detorsion (T / DT), Hyperbaric Oxygen Therapy (HBO) groups were formed in addition to Sham (S) group. In order to obtain basal values in the sham group, ovaries and blood were removed only by laparotomy, while bilateral adnexal torsion was applied for 3 hours in the other groups. In the torsion group, ovaries and blood were removed without reperfusion at the end of the ischemia period, while reperfusion was allowed in the other two groups. In the hyperbaric chamber specially designed for rats in Group HBO for one week, 8 sessions in 4 sessions of 60 minutes in the first two days following surgery, 9 sessions in 3 sessions of 6 minutes in 6, 7 and 3 days In total, 21 sessions were administered in 4 sessions of 2 sessions of 60 minutes each day. In the meantime, there was no treatment other than detorsion to the T / DT group. At the end of the treatment sessions, blood and ovaries were removed and the rats were sacrificed. Serum 8-OHDG, MDA, GSH-Px, SOD and AMH levels were measured. Ovarian edema, vascular congestion, follicular cell damage, hemorrhage, neutrophilic infiltration and loss of cohesion were evaluated histologically. SPSS for Windows version 22.0 was used for statistical analysis of the results. Results : When HBO and T and T / DT groups were compared, 8-OHdG and MDA levels were lower (p <0.05) and GSH-Px and SOD values were higher than T group (p <0.05). When HBO group was compared with T and T / DT groups, AMH levels were significantly increased (p <0.05). In addition, edema, vascular congestion, hemorrhage, neutrophilic infiltration and follicular cell damage were found to be less in HBO group compared to T and T / DT groups. Conclusion : When biochemical and histopathological findings were evaluated together, HBOT was found to be effective in reducing ovarian ischemia / reperfusion injury.