Background: Analysis of human reports and comparison with results of exper-imental animals indicate that the effects of progesterone on human not analo-gous to experimental animals fetus, many studies showed that exposure to pro-gesterone during developing of genital tract of human fetus was not teratogenic. Other studies which performed on laboratory animals found association between progesterone administration during gestation and genital malformation. Objectives: to explore the effect of progesterone in 10.2mg/kg intraperitoneal injection in mice on testis development and anogenital distance. Materials and Methods: ten pregnant mice divided into five mouse control group that injected10.2mg/kg sesame oil and treated group that injected proges-terone at dose 10.2mg/kg/day allover gestation to the seventh day postnatally, mice offspring sacrificed, the anogenital distance, weight and diameter of testis were measured ,histological slides were prepared and examined for histopatho-logical change and measurement of seminiferous tubules diameter, germinal epithelium thickness and interstitial space were done . Results: the current study found anogenital distance decrement and histopatho-logical changes in mice offspring testis as hemorrhage or congestion of blood vessels ,irregular shapes of seminiferous tubules with atrophy, detachment of spermatogenic cells from basement membrane, death of spermatogenic cells and destruction of Sertoli and leydig cells ,it is also showed wider interstitial tissue and thinner germinal epithelium. Conclusions: The present study indicate study that progesterone injected in mice at dose 10.2 mg/kg /day (the equivalent human dose allover gestation was em-bryotoxic and teratogenic, it may cause feminization of male offsprings repre-sented by decrement the anogenital distance in mice and hypospadias in human .