Molecular variants of individual components of the renin-angiotensin system (RAS) are reported to constitute the inherited predisposition to some cardiovascular diseases in man, e.g. essential hypertension or myocardial infarction. The frequency of these variants depends highly on the race and population. Therefore, we examined the M235T molecular variant of the angiotensinogen gene and the I/D polymorphism of the ACE gene in Slovak healthy population, in patients with diagnosed essential hypertension and in patients who had undergone myocardial infarction. DNA from 241 subjects was tested for the presence of M235T and I/D molecular variants. The frequency of both these polymorphisms in the Slovak population is similar to other Caucasian populations. In the group of hypertensive patients, the frequency of the M235T molecular variant was increased compared to controls, predominantly in males (0.45 vs. 0.28), while in the I/D polymorphism the incidence of the D allele was the same for both controls and hypertensives (0.49 vs. 0.50). A significant increase in the D allele frequency compared to the controls occurred in the group of infarcted patients (0.63). The increased frequency of the M235T allele in hypertensive patients compared to the healthy population confirms that the M235T variants associated with increased blood pressure in the Slovak population. In the Slovak population, I/D polymorphism of the ACE gene is associated with myocardial infarction rather than with hypertension.