Despite its wide range of application, cyclophosphamide (CP) exhibits a wide range of adverse effects including reproductive toxicity. The emerging field of zinc oxide nanoparticles (ZnO NPs) therapy may provide a new hope for prevention of CP induced gonadal toxicity. Herein, we aim to investigate the possible role of ZnO NPs as a new strategy to protect against CP induced testicular injury. Sixty adult male albino rats were divided into 3 groups; control, CP treated and CP+ZnO NPs treated groups. CP group was injected with CP (5 mg/kg/day), whereas CP+ZnO NPs group was concomitantly injected with CP and ZnO NPs (5 mg/kg/day). Testicular specimens were processed for histological, ultrastructural and c- kit immunohistochemical study. Biochemical analysis for tissue malondialdehyde and serum testosterone was done in addition to sperm morphology assay and cytogenetic study. Our results revealed that CP induced deleterious testicular histopathological, biochemical and genetic alterations that were effectively prevented by ZnO NPs.