Context: Hyperlipidemia is one of the major causes of cardiovascular problems in our population that may even cause mortality among most of the people. Atorvastatin, one of the commonly used statins for hyperlipidemia acts by lowering the total cholesterol and LDL levels in the body. It is metabolized by the enzyme CYP3A4 and CYP3A5 regulated by the POR gene. Presence of nonfunctional allele (POR*28) in POR gene may affect the hypolipidemic activity. Hence we planned our study to find the association of POR*28 genetic polymorphism with lipid lowering effect of atorvastatin in hyperlipidemic patients.