In the current study, the protective effect of a mistletoe extract (Helixor®, HLX) on Itraconazole (ITZ)induced hepatocellular injury and acute oxidative stress in rats was aimed to be investigated by histological, biochemical and comet assay methods. Four groups a control group, an HLX group (5mg/kg/14days/intraperitoneally (ip)), an ITZ group (100mg/kg/14days/oral) and an HLX plus ITZ group (5mg/kg/14days/ip+100mg/kg/14days/oral) were all created from 32 female Wistar albino rats. At the end of the experiment, AST and ALT liver enzymes, total oxidant status (TOS) levels and total antioxidant status (TAS) levels, histopathological analysis and comet assay were carried out. Highest genotoxicity, higher levels of plasma AST and ALT, higher TOS, more degeneration of liver histopathology including hepatocyte degeneration, hepatocyte apoptosis and necrosis, portal/periportal inflammation, bile ductus hyperplasia and multinuclear giant cell formation were observed in ITZ group (p<0.05). As opposed to that, administration of HLX plus ITZ improved histopathological changes and DNA damage and showed a dramatic decrease in AST, ALT and TOS levels (p<0.05) and an increase in TAS level (p<0.001) when compared to ITZ group. This study showed that the antioxidant properties of HLX administration significantly decreased acute oxidative stress and hepatocellular damage in rats given ITZ.