Abstract: Preliminary studies on the effects of dietary supplementation with Gnetum africanum leaves on some biochemical, haematological and histological parameters were investigated in female rats in which liver damage was induced with paracetamol. Thirty rats were divided into six hepatotoxic and non-hepatotoxic groups and were fed with 5 and 10% Gnetum africanum-supplemented diet. Weight changes and parameters including alanine transaminase, aspartate transaminase, total protein, glucose, total triglycerides, total cholesterol, reduced glutathione, lipid peroxidation, packed cell volume, white blood cell and differentials count, were determined using standard methods. The consumption of a Gnetum africanum-supplemented diet did not significantly change the weight of the animals and the levels of protein, alanine transaminase and aspartate transaminase. Reduced glutathione and triglycerides were significantly increased (p<0.05) in the hepatotoxic group while triglycerides were reduced in non-hepatotoxic group fed 10% Gnetum africanum-supplemented diet. Glucose was also significantly reduced (p<0.05) in the two groups. Cholesterol and lipid peroxidation levels did not change significantly in all the animals. PCV was significantly reduced (p<0.05) in hepatotoxic groups fed Gnetum africanum-supplemented diet. The hepatotoxic control and group fed 10% Gnetum africanum-supplemented diet had significant reductions in neutrophils (p<0.05). WBC levels did not change significantly. Additional histological changes observed in the photo micrograph of a cross section of the liver of the rats in the hepatotoxic groups showed necrosis and some regeneration in the group fed Gnetum africanum-supplemented diet.