The study was conducted on two groups of individuals. Group A consisted of 20 healthy volunteers who were fed garlic for 6 months and then followed for another 2 months without garlic. Garlic administration significantly lowered the serum cholesterol and triglycerides while raising the high-density lipoproteins. Group B consisted of 62 patients with coronary heart disease with elevated serum cholesterol. They were randomly divided into two subgroups: B1 was fed garlic for 10 months while B2 served as a control. Garlic decreased the serum cholesterol (p less than 0.05), triglycerides (p less than 0.05) and low density lipoprotein (p less than 0.05) while increasing the high-density fraction (p less than 0.001). The change reached statistically significant levels at the end of 8 months and persisted for the next 2 months of follow-up. Thus, the essential oil of garlic has shown a distinct hypolipidemic action in both healthy individuals and patients of coronary heart disease.