Background: The essential arterial hypertension must be regarded as a complex and heterogeneous disease. Its degree of severity and time of manifestation is determined by several genetic factors and environmental implications. This thesis deals with the association of arterial hypertension and three candidate genes, namely the GNB3-(C825T)-, AGT-(C659T)- and p22-phox-(C242T)-polymorphism. Material and Methods: The sample consisted of European Caucasians of Central Germany, 80 patients (48,7±7,0 years, 78,8% males) affected by hypertension and a group of 200 healthy long-standing blood donors (47,5±7,7 years, 79,0% males). Patients were included if they have been already suffering from hypertension for at least 5 years before being aged 55. Furthermore this hypertension had to be constituted either by blood pressure of >= 160/>= 95 mmHg or stage III hypertensive organ damage according to WHO criteria. After a clinical and biochemical characterisation of each patient DNA was extracted from their venous blood. The genotyping was performed by PCR and RFLP methods. Results and Conclusions: Regarding all patients this study could not prove a significant association between the GNB3-(C825T)-polymorphism and hypertension. However, using a recessive genetic model a significant association of the hypertensive homozygous T-allele carriers (p=0,042; OR=3,0) especially within the male subgroup (p=0,015; OR=4,7) and among patients who developed an arterial hypertension at the age of 40 or later (p=0,013; OR=9,52) was shown. These results suggest a spezific age and gender dependent pathogen effect of this polymorphism. For the AGT-(C659T)-polymorphism a significant association between the mutant T-allele and arterial hypertension was found for patients diseased at the age of 40 or later (p=0,002; OR=4,4). Moreover, significantly higher factor VII plasma levels of patients who did not receive an anticoagulant therapy were detected (p=0,049). This could be either caused by an increased transport capacity of phyllochin or a reduced activity of the anti-protease. Hypertensive carriers of the mutant T-allele of the p22-phox-(C242T)-polymorphism had significantly more frequent undergone a coronary surgical intervention (p=0,034; OR=3,7). This suggested prognostic association must be confirmed by further prospective "follow-up"-studies. The PAI-1 plasma concentration of patients carrying the mutant p22-phox-(C242T)-T-allele was significantly lower (p=0,048) assuming a protective effect concerning arterial hypertension. Further studies should be undertaken to confirm these results in larger samples and different ethnic groups.