This study aimed to determine whether ACE I/D polymorphism, as a genetic factor located within one of the genes responsible for controlling blood pressure, affects human blood pressure, with an emphasis on hypertension. The remaining factors studied in this work were gender and age as well as, in a broader sense, environmental factors: obesity, fat components in the blood and smoking habit. The sample was drawn from the population isolate of the island of Vis and consisted of 140 persons 40 to 81 years old. A positive correlation was established between systolic pressure and age, BMI and triglyceride concentration, and between the diastolic blood pressure and BMI and triglyceride concentration, as well as a negative correlation between diastolic blood pressure and the number of smoking years and smoking index. A significant influence on the increase of blood pressure in men had the concentration of triglycerides, while in women it was the BMI. Since ACE I/D polymorphism is not located in the coding region of the gene, it was supposed that it showed the effect of another polymorphism that is functional and in the linkage disequilibrium with it. The effect of ACE I/D polymorphism has been shown to obey the recessive model, i.e. the „risk“ allele influenced the development of hypertension only in its homozygous form. The influence of ACE I/D polymorphism on the development of hypertension was found also after taking into account the other risk factors such as gender, age, BMI and the concentrations of cholesterol, HDL and triglycerides as well as smoking index. Comparison between the general population of Croatia and the population of island Vis confirmed the suitability of this isolated population for genetic research of hypertension as a complex disorder.