To investigate the mediating role of oxidative stress and inflammation in the relationship between polycyclic aromatic hydrocarbon exposure and increased blood pressure, a study was conducted involving 746 petrochemical workers. Participants were selected and divided into normal blood pressure group and hypertension group based on their blood pressure values. Ten mono-hydroxylated polycyclic aromatic hydrocarbons(OH-PAHs) and six oxidative stress biomarkers(OSBs) in urine were determined. White blood cell count(WBC) was derived from workers′ blood routine examination results. The associations between urinary OH-PAHs, urinary OSBs, peripheral WBC and blood pressure were analyzed by regression models, the roles of OSBs and WBC in the relationship between OH-PAHs and blood pressure were evaluated by mediating effect model. The results indicated that 2-hydroxynaphthalene(2-OH-Nap) and 2&3-hydroxyfluorene(2&3-OH-Flu) levels in hypertension group were significantly higher than those in normal blood pressure group(P<0.05). OH-PAHs were significantly correlated with 6 OSBs(P<0.001). For each unit increase in concentrations of 2-OH-Nap and 2&3-OH-Flu, the peripheral blood WBC increased by 17.0%(β=0.170, P=0.002) and 23.3%(β=0.233, P<0.001), respectively. Additionally, for each unit increase in urinary 8-iso-prostaglandin F_2α(8-PGF_2α) and peripheral WBC, the risk of developing hypertension increased by 6.16 times(R_O=6.16, P=0.031) and 27.8 times(R_O=27.8, P=0.018), respectively. The relationship between urinary 2-OH-Nap and diastolic blood pressure was partially mediated by 8-PGF_2α and WBC, with a mediation ratio of 21.0% and 37.0%, respectively. Only WBC partially mediated the effect of 2&3-OH-Flu on blood pressure elevation. In conclusion, polycyclic aromatic hydrocarbon exposure among petrochemical workers primarily increases the risk of hypertension through the induction of inflammatory responses.