This study investigated the toxic effects of silver nanoparticles (8.67-26.3 nm) on body weight, organs body weight ratio and oxaditive status of male Sprague Dawley rats over a period of three months. In this experimental study, 100 male Sprague Dawley rats were categorized in four groups including control group and three experimental groups (n=25 in each group). The rats in the experimental groups were orally intubated 5 mg/kg, 25 mg/kg and 50 mg/kg of AgNPs solution by gavage, five days a week. Samples of blood were taken from the rats for oxidative stress assessments. Afterwards, lungs, kidney, liver and brain removed and weighted to calculate organs body weight ratio. The results demonstrated a statistically no significant change in final body weight nor organs relative weight % , oxidative stress condition were investigated with increase MDA level and decrease SOD, CAT and TAC level in serum.