Background:mitomycin-C (MC) is an anti-cancer drug against several tumor types, including colon, breast and head and neck. In this demonstration, the genotoxic effects of mitomycin-C on DNA content and testicular tissue of male albino mice Mus musculus were studied.Materials & Methods: mitomycin-C treated animal was injected intrapretonialy with tested doses of mitomycin-C single time at the first day of the experiment.  Comet assay was used to detect the DNA damage in mice lymphocytes and the mean of total comet score was increased by dose and time among all treated groups. Results:the histological alterations caused in the testis of mice after mitomycin-C treatment displayed variable changes in both the seminiferous tubules and the interstitial tissue. Changes in seminiferous tubules were represented by hypoplasia of the germinal epithelium and spermatogenic arrest at various stages of spermatogenesis. The most prominent changes reported in the intertubular tissue were represented by the presence of a homogeneous and intensely eosinophilic ground substance in the interstitial areas, congestion of blood vessels as well as haemorrhage. The histological changes were also significantly increased by time and dose.