This study was performed to investigate the distribution of indoor air pollutants in medical facility in Gyeonggi-do area from February to November, 2012, and to conduct the health risk assessment from obtained data. PM10, CO2, formaldehyde, CO, and total bacteria count(TBC) did not exceed the maintained standards, but mean concentration of TVOC was 402.3 ㎍/㎥ and thirteen of them exceeded the recommended standard. In the concentration distribution of pollutants for the monthly samples, CO2, formaldehyde, TVOC, TBC were the highest level in August. From the factor analysis of indoor air pollution provided three factors; the first factor was seasonal factor (indoor temperature and humidity, TBC and formaldehyde), the second factor was ventilation factor (CO2, PM10 and CO), and the third factor was building(or interior) factor (TVOCs). In the health risk assessment results, the excess carcinogenesis of formaldehyde for resonable maximum exposure worker was 1.21×10-4 which means exceeding the cancer criteria(1.0×10-4). We confirmed the probability of health effect caused by TVOC. The lifetime excess cancer risk of carcinogens(benzene, formaldehyde) and hazard quotient of non-carcinogens(toluene, ethylbenzene, xylene, styrene), and risk of regulation substances(PM10, CO2) were safety level for inpatients and out patients. Keywords : indoor air pollutants, medical facility, health risk assessment, formaldehyde