Low levels of pesticides persist in the environment and can affect the health of exposed subjects. Oxidative stress is considered as one of the mechanisms responsible for the adverse effects on human health and some molecules may represent useful biomarkers for the evaluation of this physiological balance. This study investigated the role of these biomarkers, such as advanced oxidation protein products (AOPP), advanced glycation end‑products (AGE) and reactive oxygen metabolites (ROMs) in relation to genetic polymorphisms of paraoxonase (PON)1, PON2, glutathione S‑transferase pi 1 (GSTP1), glutathione S‑transferase theta 1 (GSTT1) and glutathione S‑transferase mu 1 (GSTM1). An increase in the levels of these biomarkers is usually inversely associated with the depletion of the biological antioxidant potential (BAP). The results revealed a statistically significant difference in the sex‑dependent variation of AGE, BAP, AOPP and ROM protein levels. Furthermore, an association between the PON2 S331C gene polymorphism and the serum levels of AOPP, ROMs and BAP was found. Thus, compared with AGE, the levels of AOPP and ROMs provided a more sensitive biomarker, with an improved association with the PON2 genotype. Such an association strengthen the importance of PON in the occurrence of oxidative stress. According to these results, an individual's genetic background may be taken into account for the health surveillance of individuals occupationally exposed to pesticides, in order to define a cluster of highly susceptible workers so as to guarantee greater protection.