Abstract: Background and Objective: In spite of therapeutic effect of tamoxifen on the breast cancer, it has some side effects on the liver including non-alcoholic fatty liver disease. In this study the effects of Rosa canina distilled water on the tamoxifen-induced fatty liver and oxidative stress status in male rats were investigated. Materials and Methods: Twenty four adult male Wistar rats were randomly divided into 4 groups of 6: 1st group: Untreated control rats (C), 2nd group (T): The rats received tamoxifen, 3rd group (T+R): Rats received tamoxifen and Rosa canina distilled water and 4th group (R): Rats received only Rosa canina distilled water. Tamoxifen at 1 mg kg–1/day was injected subcutaneously for 7 days and the rats received orally Rosa canina distilled water at 1 mL/rat/daily for 14 days. At the end of the study, animals were studied for serum biochemical parameters (glucose, lipid profile, BUN, creatinine, uric acid, urea, ALT, AST, ALP, total protein, bilirubin, oxidative stress indices, sperm analysis and histology of the liver. The data were analyzed with SPSS software version 20 and expressed as Mean±SD. Results: Rosa canina distilled water improved liver enzyme and renal function indices which disturbed due to tamoxifen treatment. While tamoxifen enhanced lipid peroxidation, Rosa canina distilled water reduced it. In addition, tamoxifen reduced the mobility, morphology and viability of sperms, but the Rosa canina distilled water enhanced the sperm parameters. Histological results also confirmed the adverse effect of tamoxifen and the favorable impact of the Rosa canina distilled water on the liver structures of animals. Conclusion: Rosa canina distilled water could modulate tamoxifen-induced fatty liver as well as improving the sperm parameters.