Nicotine is an alkaloid and it is the primary psychoactive chemical found in tobacco plants. Therefore cigarettes are very addictive Objective: The aim of this study was to evaluate potential impact of zinc oxide nanoparticle on the possible testicular toxicity induced by nicotine. Methods: 24 adult male albino rats were divided into four groups; negative control group, zinc oxide nanoparticle group: rats were received 5 mg/kg/day zinc oxide nanoparticles orally, nicotine treated group: rats were administered nicotine (1 mg/kg/day) intraperitoneally and nicotine with zinc oxide nanoparticles: rats were treated with nicotine and zinc oxide nanoparticles daily for 28 days. Serum testosterone level, testicular malondialdehyde, SOD and catalase activities were measured. Testes were examined by light and electron microscopes as well. Results: Significant decreases of serum testosterone level, testicular SOD and catalase activity and significant increase of testicular MDA in nicotine treated group when compared with control group were detected. Zinc oxide nanoparticles administration reversed these changes. Conclusion: Zinc oxide nanoparticles ameliorated nicotine induced testicular dysfunction.