The aim of this study was to detect the cytogenetic effects of Dexamethazone drug by using head sperm abnormalities test on white mice (Musmusculus) fivety five male mice were used in this study, these animals were divided into five groups. The first was the negative control group while the second was treated with MMC as positive control, and the three groups (45 mice) treated with three doses (0.02, 0.04 ,0.08mg/ from dexamethasone drug.The result refer that the dexamethasone cause increasing in many kind of head sperm abnormality (p<0.01).Which indicate the high side effect of this drug on germ cells so we can conclude that this drug may permanently sterilize in the mice.