This study investigates effect of exhaust outlet location on airflow and particle distribution in an operating room with laminar ventilation system (LAF) via computational fluid dynamics (CFD). Four different exhaust opening configurations are comparatively examined: floor level, central level, ceiling level and floor & ceiling level. Three different particle diameters (5,10 and 20 mu m) are considered for a constant value of the air change rate (30 ACH). Deposited particle numbers to operating table and to instrument table are given and compared for different particle diameters and exhaust outlet cases. It is shown that the exhaust configuration in which both floor & ceiling level air outlets employed together shows the best performance in terms of lowest particle deposition to the operating table. For this case, compared to original floor level exhaust outlet design, the total number of particles deposited on the operating table decreased by 64% for the smallest particle diameter (5 mu m) and 26% for the largest particle diameter (20 mu m).