Endothelium; effective in vascular tonus, blood tension, blood flow and coagulation system is the biggest endocrine organ with 1800 gr. weight in human body. The endothelium releases nitric oxide, which maintains vascular integrity. In endothelial dysfunction the balance between releasing vasodilatatory and vasoconstrictory factors is changed. In the presence of essential hypertension defection in endothelium-dependent vasodilatation and increasing sensitivity to vasoconstrictors could increase vascular resistance. Although some beneficial results with angiotensin converting enzyme inhibitors, carvedilol, angiotensin-II and endothelin receptor antagonists were reported in patients with endothelial dysfunction the effectiveness of these drugs is still debate. Also the decreasing of arterial pressure was not always shown to be parallel to the restoration of endothelial dysfunction. In the future according to genetic studies, the increased use of nitric oxide releasing genes therapy will have a more effective role in regression of endothelial dysfunction.