Androgenic-anabolic steroids are used widely by many athletes in order to increase muscle mass and strength. Since plasma total homocysteine, an independent risk factor of vascular diseases, is higher in men than in women, it has been proposed that androgenic hormones could increase the plasma total homocysteine level and it might play some role in sudden death when used at supraphysiological doses. To study the association between the use of androgenic-anabolic steroids and plasma homocysteine level, nandrolone decanoate was administered in 3 and 10 mg/kg doses to male rats by intramuscular weekly injections. Control animals received the solvent of nandrolone decanoate. After 14 weeks, plasma total homocysteine level was measured. In order to make sure about the adequacy of doses and bioavailability of drug, testes parameters were also considered. While all testes parameters were suppressed significantly, no association between androgenic-anabolic steroids use and total homocysteine level was found.It is concluded that chronic administration of nandrolone decanoate does not have any significant effect on plasma total homocysteine of male rats. Thus, factors other than plasma total homocysteine level may contribute to increased cardiovascular events after chronic abuse of androgenic-anabolic steroids.