The protective effects of the ethanol extract of Smilax excelsa L. (SE) leaves were investigated on testicular tissue of rats with a torsion model in this study. The chemical composition of the extract was detected by means of liquid chromatography with tandem mass spectrometry (LC-MS/MS). SE extract was given for 21 days before torsion was created in the treatment group. The sperm parameters of the torsion group were impaired, and there was an increase in MDA level as well as a decrease in GSH level and GPx activity compared to the control group. TNF-α and NF-κB levels in the torsion group increased as compared to those in the control group. The expression levels of Nrf-2 and HO-1 were lower in the torsion group than those in the control group. The SE pretreatment group has improved sperm, oxidative stress, and inflammatory markers when compared to the torsion group, and the Nrf-2/HO-1 pathway was activated. PRACTICAL APPLICATIONS: Smilax excelsa L. is a plant with economic value used in traditional medicine in the treatment of stomachache, bloating, and breast cancer in Northwest Anatolia. It has an antioxidant effect due to the flavonoids and anthocyanins it contains. The protective effect against ischemia-reperfusion-induced tissue and reproductive damage in testicular tissue were demonstrated with the study. When the histological examinations of the tissues were evaluated, it was found that morphological structure of the tissues was retained in the treatment group. The findings indicate that SE prevents tissue damage in the torsion model by antioxidant and anti-inflammatory effects and activating Nrf-2/HO-1 pathway.