Pyrethroid were synthetic analogues insecticides as pyrethrins. They are known to be effective in insects because they are degraded by rapid metabolism in mammals. However, health effects that occur are not clearly known in human. In this study, we evaluated the effect of exposure of low concentrations of insecticide, rather than high concentration exposure, on human health.This study was performed on 5474 adults aged 19 years and older based on the Second Korean National Environmental Health Survey(KoNEHS 2012–2014). We used regression analysis to examine the effects of 3-PBA(phenoxybenzoic acid, as metabolite of pyrethroid) levels in urine on the complete blood count(CBC; white blood cell, red blood cell, hemoglobin, and platelet) and liver enzymes(AST, ALT, Γ-GPT). As clinical laboratory values are different according to sex, they are stratified. Thus, urinary 3-PBA/Cr, liver enzymes were transformed logarithmically due to their skewed distribution.Geometric mean concentrations of urinary 3-PBA were 1.94μg/L/Cr in total, 1.59μg/L/Cr in men, and 2.41μg/L/Cr in female, respectively. Association between log-transformed urinary 3-PBA and liver enzymes were not statistically significant. However, association between log-transformed urinary 3-PBA and RBC and hemoglobin were statistically significant, respectively (adjusted coefficient=-0.018(0.009), p=0.0425;-0.043(0.025) p=0.0791). After stratification, there was a negative association between log-transformed urinary 3-PBA and RBC and hemoglobin only for male group (adjusted coefficient=-0.024(0.035), p=0.0385;-0.097(0.011) p=0.0064).Low concentrations of pyrethroid exposure showed a statistically significant decrease in RBC and hemoglobin in humans. Liver enzymes, however, tended to increase, although not statistically significant. The results of this study need to educate the public about not being exposed to pesticides, and in order to do so, we must try to find these exposure factors in our living environment.