Many techniques have been applied to comprehensive regional planning through the processes of goal-building, research and analysis, plan-establishing, implementation-scheduling, and evaluation. Operations research(OR) is one of those techniques. OR has been developed in such fields of military operations, industrial engineering and business management during the last three decades in several developed western countries. It is a recent tendency for public administrators and researchers to be interested in OR for their scientific decision making. Therefore, we see that OR has not only a weak basis on, but a few practical applications to urban and regional planning. Such situation is worse in developing countries. This paper aims at investigating the possible basis and limitations or obstacles of OR application to public decision making, especially regional planning. A practical example of OR application to regional planning in Korea and its evaluation will be introduced.