SummaryHemolytic phenomena observed in congenital or acquired erythroenzymopenias express modifications resulting from alterations of the metabolic pathways. Enzymatic deficiences affecting the rate of anaerobie glycolysis interfere with ATP production and consequently osmotic regulation, cellvolume control and cellviability.Erythrocytic enzymopathies related to the pentose phosphates shunt alter the oxydoreduction potential of the cell, affect reduced glutathion stability and peroxide detoxication. They had to membrane lesions through thiol and lipid denaturation and facilitate oxidative hemolysis.