Trichlorophenols such as 2,4,5-trichlorophenol (2, 4,5-TCP) and 2,4,6-trichlorophenol (2,4,6-TCP) are organochlorine compounds to which the general public can be exposed via contaminated food, water, and air. This study assessed exposure to 2,4,5-TCP and 2,4,6-TCP in Koreans age 18-69 years based on the Korean National Human Biomonitoring Survey conducted in 2009. Using data from 1,865 representative Koreans, we found that the geometric mean urinary concentrations of 2,4,5-TCP and 2,4,6-TCP were 83.4 pg/mL [95 % confidence interval (CI)=78.6-88.6] and 0.39 ng/mL (95 % CI=0.35-0.42), respectively. The creatinine-adjusted geometric mean 2,4,5-TCP and 2,4, 6-TCP levels were 78.8 ng/g creatinine (95 % CI=73.8-84.1) and 0.36 μg/g creatinine (95 % CI=0.33-0.40), respectively. Of the Korean adult population, about 67.5 and 87.5 % had respective urine 2,4,5-TCP and 2,4,6-TCP concentrations >0.05 ng/mL (the limit of detection, LOD). Urine 2,4,5-TCP concentrations were significantly associated with age and place of residence, whereas urine 2,4,6-TCP concentrations were higher in rural residents. These findings suggest that most Koreans had detectable levels of 2,4,5-TCP and 2,4,6-TCP in their urine and that the body burden of 2,4,5-TCP and 2,4,6-TCP varied according to demographic and geographic factors.