Objective: The aim of this study was to demonstrate the radioprotective effects of ginkgo biloba (G. biloba, EGb 761), probiotic Saccharomyces boulardii (S. boulardii) and N-acetylcysteine (NAG) on radiation-induced small intestine injury via immunohistochemical evaluation using pancadherin, a cell adhesion molecule. Material and Methods: A total of 48 female Wistar albino rats were divided into five groups: negative and positive controls, G. biloba, S. Boulardii and NAC groups. The radioprotective agents were started as twice per day by gavage regimen the day before the first radiation exposure. External abdominal radiotherapy, 5Gy/day, under general anesthesia was administered on five consecutive days ending up with five fractions in total (25Gy). Radioprotective agent administration was completed to 14 days and the rats were sacrificed on the 15(th) day. After extraction of the jejunum, tissue morphology, integrity and the number of villi were evaluated in H&E stained slides and pancadherin immunoreactive cells were evaluated immunohistochemically. Results: The disruption of mucosal morphological integrity, degenerative spaces and edematous cavities were observed after radiation-induced jejunum injury. The contribution of the radioprotective effect of all agents were shown on tissue integrity. However, the most prominent effect was noted in the NAG group. In addition, the numbers of villi and pancadherin immunoreactive cells in the NAG group were significantly higher than the other groups. Conclusion: NAG is a good agent in protecting against and ameliorating adverse effects of radiotherapy in a rat model.