The aim of the study was to assess the existence of possible associations among frequent polymorphism in angiotensinogen gene and some risk factors for essential hypertension, especially BMI and smoking. 192 control subjects (age 45.87+/-3.0) and 206 patients with the essential hypertension (age 48.71+/- 8.42) were compared at three angiotensinogen gene polymorphisms considering BMI and smoking status. No significant differences in genotype and/or allelic distribution for either A (-6) G ATG or M235T or T174M polymorphisms between the hypertensive and control groups were proved. Significantly more hypertensives than control persons with BMI above 25 kg/m2 were observed (Pcorr=0.009), independently on sex distribution. 44.6% of smokers in control group vs. 46.0% of smokers in hypertensive groups were found. No significant difference in concurrence of BMI above 25 kg/m2 and positive smoking status between control and hypertensive subjects was found. Statistically significant differences were found between control and hypertensive subjects when compared distributions of subjects with certain genotypes of the three examined polymorphisms considering BMI (Pcorr=0.0002 for AA+AG of A(-6)G ATG, Pcorr= 0.01 for CC+CT of T(174)M ATG and Pcorr=0.01 for MT+TT of M235T ATG). No functional relations among obesity and the examined polymorphisms in vivo are known. We conclude that different distribution of BMI could influence results of analyses of angiotensinogen gene polymorphisms in essential hypertension-control studies.