The results of our studies will have impact on general knowledge on ethiopathogenesis of coronary artery disease and arterial hypertension. The results will directly effect the treatment modalities in everyday practice. The study of diffuse coronary artery disease (CAD) has demonstrated that diffuse CAD is a special pathological entity. There were inflammatory changes in andarterectomised vessel wall so as in the wall of angiogenetically arised vasa vasorum of atherosclerotic plaque. These changes are most probably the reaction to the presence and infection with Chlamydia Pneumoniae. Our findings might change the therapeutic strategies in CAD. The DD genotype of the insertion/deletion (I/D) angiotensin-I converting enzyme (ACE) gene polymorphism was independent risk factor for myocardial infarction. Sex difference was demonstrated in the effect of ACE-DD genotype on the risk of premature myocardial infarction. DD genotype was a risk factor in men but not in women. Apo E gene polymorphism affected the cholesterol metabolism - namely subjects with e3e4 genotype were associated with increased LDL cholesterol level. The gene polymorphism of atrial natriuretic factor was demonstrated as potential genetic risk for essential arterial hypertension, especially in interaction with obesity. The results of research on hypertensive rat model failed to confirm our hypothesis about the importance of hypoxia on spontaneous carcinogenesis in a group of animals treated with calcium antagonists.