This study aims to examine the relationships between total quality management(TQM) practices and operational performance perceived by employees who are in different organization types, R&D organization and Non-R&D organization in manufacturing companies. Operational performance is defined as the degree of operation efficiency in the perspective of quality, delivery, and cost. Our study showed that the degree of TQM practice has significant difference in organization type. In case of R&D organization, the categories of customer focus and process management were the strongest significant predictors of operational performance. Therefore, the optimal TQM practices for R&D organization can be obtained in consideration of customer focus and process management.