Many studies have been carried out in order to determine the toxicity of medicinal plants. The objective of this study was to compare and analyze the hepatic response against two doses of Nerium oleander, (N. oleander) kaner leaf decoction. Aqueous leaf decoction was injected intramuscularly into both hind limbs of male rats (200∓10g), assigned into three categories (n=4): control group with no treatment; group I, injected with 5 ml/ kg; and group II injected with 10 ml/ kg of leaf decoction, respectively. Animals were sacrificed 6 h after administration and hepato-histological changes were then observed. The decoction induced an acute phase reaction reflected by a more significant recruitment of inflammatory cells in group II than in group I and controls, as observed by histological studies. These results indicated that both doses can induce an acute-phase condition. Hence, traditional practice of medicinal plants without preliminary dose assessment must not be administered.