Abstract: Study investigated the effect of oral administration of gold-silver nanoparticles on rat biochemical parameters and tissue morphology. Wistar rats weighing approximately 180±7 g were randomly assigned into four groups. Animals in the control group received distilled water once daily for 30 days while, those in the treatment groups were administered 10, 50 and 100 mg kg–1 b.wt. gold-silver nanoparticles. The rats were sacrificed under slight anesthesia, 24 h after the last treatments. Blood and vital organs including the heart, kidney and liver were collected and prepared for biochemical and histopathological determinations. Exposure to Ag/Au nanoparticles altered the rat serum lipid profile; lowering the HDL-C while raising the atherogenic index. Exposure of Ag/Au nanoparticles in rats caused significant alteration to the levels of serum albumin, total protein, bilirubin, urea and creatinine. The activities of alanine transaminase, aspartate transaminase and alkaline phosphatase in rat serum and tissues were also significantly altered by Ag/Au nanoparticles exposure. The histopathological examination revealed inflammation and cellular degeneration caused by exposure to the Ag/Au nanoparticles. We show evidence that Ag/Au nanoparticles elevated atherogenic index, as well as caused biochemical and morphological alterations, reminiscent of cellular injury.