The action of glucose as an osmolyte in relation to blood cells is not well-characterized in the literature. This study aimed to study the influence of glucose concentration on the stability of red blood cells. The stability of erythrocytes was evaluated by the half-transition point obtained from the curves of lysis induced by glucose in the absence of salt or by increase in medium hypotonicity in the absence and the presence of different concentrations of glucose. In the presence of 0.9 g/dl NaCl, there was no hemolysis with increasing concentration of glucose from 0 to 10 g/dl. In the absence of NaCl, the dependence of hemolysis with the 0-10 g/dl glucose was described by a decreasing sigmoid, with fully lysed and fully protected cells being encountered in the presence of 0-2 and 4-10 g/dl glucose, respectively. The possible origin of such stabilization effect is discussed with base of what is known about osmostabilization of biological complexes and about the influence of glucose on the rheological properties of erythrocytes.