The loss of nerve cells and the accumulation of pathological protein deposits comprise the common features of Alzheimer’s disease (AD) and Creutzfeldt-Jakob disease (CJD). Despite our constantly broadening knowledge of the pathogenesis of neurodegenerative diseases, the precise molecular mechanisms of the pathological processes underlying this group of diseases still remain to be unambiguously elucidated. Recently, evidence suggesting a crucial role for the oxidation stress in the development of these neurodegenerative diseases has significantly increased. An association between the accumulation of pathological protein deposits and increased generation of reactive oxygen species has been proposed in both AD and CJD. In the light of increasing evidence documenting the occurrence of DNA damage as a consequence of oxidative stress, involvement of DNA repair genes in the pathogenesis of these diseases was implicated. The product of OGG1, APE1 and XRCC1 genes play various roles in the removal of oxidative-stress-induced DNA damage, and in the protection of cells against the consequences of oxidative stress, including cell death. The enzymes comprising the DNA repair system play a significant role in maintaining an intact genome. Therefore, the dysfunction of this system or its partial impairment may lead to an accumulation of errors which ultimately lead to cell death.