This paper consists of a study of the distribution of the erythrocyte glyoxalase (GLO-I E.C.4.4.1.5) within the population of the Bulgaria. Blood samples of 2559 clinically healthy subjects (males and females) of Bulgarian origin from south-central and south-eastern region of Bulgaria aged from 18 to 45 years were used in the study. The phenotype of GLO-I were done by the conventional methods. All established tests are only classical types of GLO-I. The distribution of phenotype was the following: 1-1- 14,03% individuals; 2-1 - 49,79% and 2-2 - 36,18%. The obtained allelic frequencies are those indicated fortwith: GLO-I 1 = 0,3892 and GLO-I 2 = 0,6108. The differences between the observed and theoretically expected values, evaluated with x-criterion, are insignificant (P>0,05) and resulting phenotype distribution adheres closely to Pearson law. The concordance between the observed and expected values is good and by Hardy-Weinberg law indicates that the studied population is in a state of genetic equilibrium with respect to the studied system. The results from the present investigation were compared with results in literature about other populations and it was found out that the Bulgarian population is part of the larger group of European people in terms of the studied factors.