This study was to assess the lifetime cancer and non-cancer risk on exposure to volatile organic compounds (VOCs) and formaldehyde of worker and user at public facilities in Korea. We measured the concentrations of formaldehyde and VOCs in indoor air at 160 public buildings that 5 kinds of public facilities (30 hotel, 30 fitness center, 25 gosiwon, 30 reading-room and 45 video-room) all over the country. There were estimated the human exposure dose and risks with averages of the using-time and frequency for facility users and office workers, respectively. Carcinogens (benzene and formaldehyde) were estimated the lifetime excess cancer risks (ECRs). Non-carcinogens (toluene, ethylbenzene, xylene, and styrene) were estimated the hazard quotients (HQs). HQs of four non-carcinogens did not exceed 1.0 for all subjects in all facilities. Higher HQs of toluene were observed at the reading-room. The average ECRs of formaldehyde and benzene for facility worker and user were 1×10^-4~1×10^-6 level in all facilities. The estimated ECRs for reading-room were the highest and the fitness center and gosiwon were the next higher facilities. Because lifetime ECRs of carcinogens exceeded 1×10^-4 for facility worker in the most facilities, risk management of formaldehyde and benzene in the facilities was necessary. IAQ guidelines should be determined strictly to prevent occurrence of disease caused by poor IAQ beforehand.