The rather common coexistence of arterial aneurysm and systemic hypertension may be attributed to their respective frequency as clinical findings. The development of hypertension secondary to renal ischemia that can occur as a complication of certain types of aneurysmal disease is well recognized. Less well appreciated is the evidence to implicate hypertension as a factor in the pathogenesis of arterial aneurysms, perhaps in their progressive enlargement, and even in rupture. Furthermore, after resection of an aneurysm, systemic hypertension adversely influences survival, and it is an important contributing factor in the development of false aneurysms. A relation between hypertension and aortic dissection has received more recognition. Just how systemic hypertension contributes to the occurrence of aortic dissection is not clear, but the effective control of hypertension has the potential for decreasing the incidence of aortic dissection. The curious clinical association of hypertension with the location of the primary tear in the proximal part of the descending aorta (type III or type B) has several plausible explanations.