Background: To evaluate biochemically and histopathologically the effects of nigella sativa (NS) in experimental ischemia and ischemia/reperfusion (I/R) injury in rat ovaries. Methods: Thirty-six female rats were divided into 6 groups: group I = sham operation; group II = 500 mg/kg NS + sham operation; group III = bilateral ovarian ischemia; group IV = 500 mg/kg NS + ischemia; group V = 3-hour period of ischemia + 3-hour reperfusion, and group VI: 3-hour period of ischemia + 500 mg/kg NS 2.5 h after the induction of ischemia + 3-hour reperfusion. At the end of ischemia, the bilateral vascular clips were removed, and 3-hour reperfusion was continued. IL-1?, IL-6, and TNF-? cytokine levels in serum, and superoxide dismutase (SOD), myeloperoxidase (MPO), glutathione (GSH), and malondialdehyde (MDA) levels were determined. Results: I/R increased the MDA level and MPO activity while significantly decreasing the SOD activity and GSH level when compared to the sham. The 500-mg/kg dose of NS before I/R reversed the trend in MDA levels, MPO activity, SOD activity, and GSH levels. Ischemia and I/R increased the serum levels of IL-1?, IL-6, and TNF-?, while the administration of NS decreased the serum levels of these cytokines. Conclusions: The administration of NS is effective in reversing tissue damage induced by ischemia and/or I/R in ovaries.