Exposure to environmental tobacco smoke (ETS) could adversely affect health. The aim of this study was to quantify the contribution of ETS exposure in nonsmokers of entertainment facilities. We simultaneously measured nicotine and nitrogen dioxide (NO2), which are known as indicators of ETS, concentrations in indoor internet cafe, billiard, karaoke, bar and restaurant, and estimated exposure level of other harmful agents occurred from tobacco smoking. Mean nicotine concentration (10.57±2.53 ㎍/㎥) of internet cafe was the highest comparing to other facilities, whereas mean concentration of restaurant where was non-smoking area was 0.28±0.08 ㎍/㎥. There was statistically not correlated between NO2 and nicotine concentrations in entertainment facilities. Therefore, the use of NO2 concentration as indicator of ETS exposure may not be available. To date, there are no standards about each agent occurred from ETS. Consequently administrative control and regulation, and further researches in relation to ETS exposure should be needed. Keywords : Smoking, nicotine, Nitrogen dioxide, ETS