Nandrolone decanoate (ND) is one of the most commonly abused anabolic-androgenic steroid compounds in the world. Owing to the abuse of ND among rabbit breeders to increase body weight together with the shortage in studies that deal with ND administration in rabbits, the present study was designed to evaluate the effects of ND on reproductive performance of rabbits. Four groups of adult male rabbits were used; the first one was control, while other groups were injected with ND in two different doses at day one and at day 15 of the experimental period (8 weeks). The obtained results cleared that ND had, in general, dose-dependent harmful effects. Administration of ND led to significant decrease of rabbit body weight; arrested spermatogenesis that was accompanied by sever reduction of inseminated spermatozoa and their motility reached to oligospermia; reduction of seminal plasma biomarkers, alkaline phosphatase and fructose; and markedsuppression of testicular gene expressions,androgen receptor(AR) andcytochrome P450(CYP3A6)genes. It could be concluded that ND administration, specifically in high dose, is not recommended for use as an anabolic in male rabbit breeding. Further studies are needed to determine ND tissue residues and safety limits for use.