Ovarian torsion is a surgical emergency affecting not only the ipsilateral ovary but also contralateral ovary. Although the conventional treatment is salpingo-oophorectomy, recent studies advocate detorsion. We hypothesized that iloprost, an analogue of prostacyclin with cytoprotective properties, may prevent the harmful effects of ischaemia-reperfusion injury in bilateral ovaries after unilateral ovarian torsion-detorsion in rat. In this study, 24 female Wistar-albino female rats were divided into four groups. Ovarian torsion was produced by applying vascular clamps to right ovaries. In Group I, bilateral oophorectomy was performed. In group II, bilateral oophorectomy was performed after a unilateral torsion period of 4 h. In group III, bilateral ovaries were removed, following unilateral torsion-detorsion periods each lasted for 4 h. Saline was injected i.p. 30 min before detorsion. In group IV, same experimental protocol, which was conducted in group III, was repeated. Iloprost was injected i.p. 30 min before detorsion instead of saline in group IV. Tissue levels of malondialdehyde (MDA) and nitric oxide (NO), which are the indicators for oxidative stress were determined and histopathological evaluation was performed in bilateral ovaries in all groups. The MDA and NO levels for ipsilateral ovaries of four groups were compared and no significant difference was found (p>0.05). The same comparison were done for the contralateral sides and no difference was seen either (p>0.05). In histological examination, iloprost produced improvement in I/R-induced alterations in ipsilateral and contralateral ovaries. In conclusion, these results showed that iloprost has beneficial effect on the histological appearences in both the ipsilateral and contralateral rat ovaries after unilateral torsion-detorsion. (C) 2009 Elsevier GmbH. All rights reserved.