Left ventricular hypertrophy (LVH) has been identified as an independent risk factor in coronary artery disease, sudden death, stroke and heart failure. The prevalence of LVH in patients with essential hypertension has been found to be 40% on average. Therefore, prevention and/or regression of LVH is a major therapeutic goal whether achieved by pharmacologic, mechanical, surgical or genetic means. This monograph discusses the role of ?1 adrenoceptors and their subtypes in the renal vasculature and kidney and its interaction with Renin Angiotensin System. Studeis were done in Sprague Dawley rats and it was found that at the renal resistance vessels, a multiple subtype shift of ?1 adrenoceptor subtypes occurs which generated a complex feedback on the renal AT1 receptors. ?1D adrenoceptor subtype gains functional importance in LVH with a minimal altered role of ?1A and ?1B adrenoceptors.Hence renal ?1D adrenoceptors can be a potential therapeutic target for better treatment outcomes of LVH. Parts of the studies discussed in this monograph were made possible through a short term research grant provided by Universiti Sains Malaysia 304/PFARMASI/6311060 which is greatly acknowledged.