Plumbagin (2-methyl-5-hydroxy, 1:4 naphthoquinone) isolated from the roots of Plumbago zeylanica when administered to hyperlipidaemic rabbits, reduced serum cholesterol and LDL-Chol. by 53 to 86 percent and 61 to 91 percent respectively. It lowered cholesterol/phospholipid ratio by 45.8 percent and elevates the decreased HDL-Chol significantly. Further, Plumbagin treatment prevented the accumulation of cholesterol and triglycerides in liver and aorta and regressed atheromatous plaques of thoracic and abdominal aorta. Plumbagin treated hyperlipidaemic subjects excreted more fecal cholesterol and phospholipids. In conclusion-Plumbagin feeding brings about a definite regression of atheroma and prevents the accumulation of cholesterol and triglycerides in liver and aorta.