The role has been studied of thiol compounds as indicators of bodily antioxidant defence in patients with severe gestoses. A comprehensive evaluation was done of disorders in the system lipid peroxidation/antioxidant defence, with effectiveness of their correction with ozonohemotherapy and antioxidants included into the conventional intensive therapy of patients having been studied as well. The above therapy makes for restoration of intracellular environment of erythrocytes at the expense of maintenance and augmentation of the compensatory reaction in respect of activation of the enzymic link of the antioxidant defense in blood plasma of patients.