Although Zinc oxide nanoparticles (ZnO NPs) in low doses have potentially positive effects on reproduction by their antioxidant effects, the defensive role of Zinc nanomaterials against environmental pollutants that affect male reproduction has not been adequately studied. We designed our study to assess the impact of ZnO NPs towards reproductive dysfunction induced by Benzo[α]Pyrene (B[a]P). Forty-eight mature male rats were randomly distributed into six equal groups: G1; negative control, G2&3- positive control I &II (either 10 or 30 mg ZnO NPs / kg BW); G4. (150 mg Bap / kg BW), G 5 & 6 (Co- administrated B[a]P with different concentrations of ZnO NPs). Oxidative stress biomarkers, semiquantitative real-time PCR for steroidogenic enzymes (CY11A1, StAR, and 3β- HSD), testosterone levels and histopathology in the liver, kidney, and testicles were examined for this investigation. B[a] P treated group showed significant deterioration in all reproductive parameters and induced oxidative stress. Co-administration ZnO NPs eased oxidative stress and effectively increased the expression of CY11A1, StAR, and 3β- HSD and improved histopathological changes in the examined organs. Our results using the selected doses and with Nano particle properties confirm that ZnO NPs have an obvious ameliorative effect against B[a] P.