Hypertension and Hypercholesterolemia are a major public health problem in the developed Countries.Irbesartan and atorvastatin is newly fixed dose combination used in hypertension and hyperlipideima condition. This combination therapy gives antihypertensive and antilipidemic treatment for condition of coronary artery diseases.so the analytical methods like spectroscopy and high performance liquid chromatography develop for this combination. Here, Three spectroscopy method(simultaneous equetion method, absorbance ration method, first derivative spectroscopy method) and one high performance liquid chromatography method(RP HPLC) is used for the simultaneous estimation of irbesartan and atorvastatin in formulation, bulk and synthetic mixture.This book is very helpful for researcher in area of method development, preformulation, clinical trail regarding two drug combination(irbesartan and atorvastatin).