Allium cepa has been reported to contain some phytochemicals that have possible effects on weight reduction and circulating lipids. This experiment is aimed at observing the effect of A. cepa on the lipid profile and cardiac enzyme marker of albino Wistar rats fed with high-fat diet. Exactly 48 Wistar rats were used in this experiment, and were separated into four different groups as A, B, C and D. Each group had 12rats. The groups were given feed with different compositions as: normal rat feed; A. cepa supplemented rat feed; high-fat diet and A. cepa supplemented high-fat diet respectively. Animal sacrifice was by euthanasia done by cervical dislocation. Cardiac puncture was via a cardiac puncture and drainage of the abdominal aorta was done. Standard methods were used for analysis. Comparisons were made between control and treatment groups. The result showed that the group on high-fat diet had elevated percentage increase in mean body weight during the period of study. This high weight was down-regulated in the group fed with A. cepa supplemented high-fat diet. However, the result showed no significant effect of A. cepa and the high-fat diet in the lipid profile and creatine kinase status of the Wistar rats during the experimental period of four weeks. On the cardiac risk ratio, a ratio greater than 4.5 is considered a high risk for coronary heart disease. The ratio may be decreased by increasing the good cholesterol (HDL-cholesterol) and/or decreasing the bad cholesterol (LDL – cholesterol). Conclusively, A. cepa has the tendency of reducing cardiovascular risks in animals.