This study aimed to evaluate the effect of kenaf seed oil (KSO), kenaf seed oil-in-water macroemulsion (KSOM), kenaf seed oil-in-water nanoemulsions (KSON), and emulsifier mixtures (EM) on serum lipid profile, liver oxidative status, and histopathological changes in high-cholesterol fed rats. Stability and characteristic of KSOM and KSON were carried out prior to in vivo study. Forty-two Sprague-Dawley rats were divided into 7 groups (6 rats each) and induced hypercholesterolemia by feeding high cholesterol diet (HCD) for 14 days prior to treatments. Different treatments were introduced on day 15 to 29 while supplemented with HCD and removal of HCD during treatment on day 30 to 43, except for HCD group. Body weight and serum lipid profiles were measured at 3 different points: after hypercholesterolemia was induced, on day 29, and at the end of the experiment. Relative liver weight, atherogenic index, coronary risk index, and fecal total bile acids were also determined at the end of experiment. KSON showed significantly higher stability than KSOM and FTIR exhibited good encapsulation of KSO after 1.5 years of storage. Serum total cholesterol, low density lipoprotein cholesterol, lipid peroxidation levels in HCD group without treatment were significantly higher compared to normal control group and all treatment groups. All samples demonstrated hypocholesterolemic effect, but KSON exhibited higher efficiency in cholesterol-lowering properties, weight control and decreased liver fat as confirmed by histopathological evaluation. The overall results revealed that the efficacy of different treatments was in descending order of KSON, KSO, KSOM, and EM.PRACTICAL APPLICATION: Kenaf seed oil-in-water nanoemulsion (KSON) has the potential to be used as a natural alternative to the synthetic hypocholesterolemic drug in the future. However, larger sample size and clinical trial are needed to confirm on this potential application. In addition, treatment with KSON was suggested to prevent cardiovascular disease and fatty liver.