OBJECTIVES To study the difference in blood lead level of children living in an industrial complex and those in a suburban area in Ulsan, Korea, and to investigate the trend by age and year. METHODS The study subjects consisted of 620 children living in an industrial complex and 298 children living in a suburban area of Ulsan, Korea. We analyzed their blood lead levels, using an atomic absorption spectrometer with a graphite furnace, bi-annually from 1997 to 2001. RESULTS The geometric mean levels of blood lead in children living in the industrial complex were 5.10 microg/dl, 5.36 microg/dl, and 5.41 microg/dl in the years 1997, 1999, and 2001, respectively, whereas those of children living in the suburban area were 3.81 microg/dl, 4.75 microg/dl, and 4.93 microg/dl, respectively. There was an increasing trend in the blood lead levels of children, and the differences in the levels of children living in the industrial complex and in the suburban area decreased year by year. CONCLUSIONS These results suggest that the amount of exposure to lead in children is increasing from year to year in Ulsan, Korea.