Hypercholesterolemia is a risk factor for non-alcoholic fatty liver disease (NAFLD) due to excess fat deposits in the liver. The excess fat deposits in the liver will cause a buildup of free radicals which can damage hepatocytes.(1) Components in probiotics have been proven to reduce cholesterol levels through the increase of excretion,(2) inhibition of absorption,(2) and inhibition of free radical formation.(3) Probiotics are expected to reduce MDA (malondialdehyde) levels of hepar as the end product of lipid peroxidation and the indicator of cell damage due to oxidative stress. Probiotics are also expected to increase antioxidant levels of SOD (superoxyde dismutase) in liver which protect from the negative effects of free radicals. This research was approved by the ethics committee, i.e. no. 9/Ka.Kom.Et/70/KE/XI/2018. The researcher applied a post test only control group design. The research subjects were 25 male Wistar rats (Rattus norvegicus) which were divided into 5 groups, namely C- (negative control), C+ (positive control, induced by high-fat diet or HFD), T1 (induced by HFD and given probiotic dose of 6.5×106 cfu/g), T2 (induced by HFD and given probiotic dose of 5.5×106 cfu/g), and T3 (induced by HFD and given probiotic dose of 1.65×107 cfu/g).(4) Induction of HFD was performed by giving 3 g/day of white butter.(5) Probiotic used in this study was over the counter probiotic containing Lactobacillus acidophilus, Bifidobacterium longum, and Streptococcus thermophilus. Induction and treatment were given orally using gavage for 10 weeks. At the end of treatment, rats were euthanized under anaesthesia (ketamine HCl 100 mg/kg body weight). Immediately, rat liver was taken and the MDA level and SOD activity were examined using spectrophotometric methods. The obtained data were analyzed using software to see differences in mean MDA levels and SOD activities between groups. The average levels of MDA ± SD in group C-, C+, T1, T2, and T3 were 1.43 ± 0.13 nmol/g; 4.98 ± 0.43 nmol/g; 3.63 ± 0.16 nmol/g; 3,11 ± 0,10 nmol/g; and 1.83 ± 0.06 nmol/g. One-way ANOVA analysis showed statistically differences of liver MDA levels between the groups (p<0.05). The average activity of SOD ± SD in group C-, C+, T1, T2, and T3 were 66.34 ± 3.05 %; 19.46 ± 6.60 %; 35.83 ± 2.72 %; 45.36 ± 3.86 %; and 58.30 ± 4.92 %. Analysis using one-way ANOVA showed statistically differences in liver SOD activity between the groups (p<0.05). Pearson correlation analysis showed a significant relationship between MDA levels and liver SOD activity (p<0.05). In conclusion, probiotics administration could reduce oxidative stress parameters in the liver of Wistar rats induced by HFD. There was significant decrease in liver MDA levels and significant increase in liver SOD activity due to administration of probiotics in Wistar rats induced by HFD.