The main purpose of this study was to explore how can Quality Management Practices (QMPs) be institutionalized as a successful strategic performance improvement initiative in a manufacturing organization located in Sri Lanka. Institutional Theory was incorporated as a theoretical lens to make sense of institutionalization process of the organization. Institutionalization Framework of Tolbert and Zucker (1996) which takes into the account the pre-institutionalization, semi-institutionalization and full institutionalization stages of QMPs implementation within the case organization. The study adopted the single-site case study method under the qualitative methodology. Data has been mainly collected through interviews and documentary review. The findings of this study illustrated that implementation of QMPs in the case organization is successful, because quality management has become an institutionalized practice within the case organization. It was further evident that, institutionalization of QMPs is complete when they are both accepted and taken-for-granted as part of the way people feel and think and the way they usually do things. As a result of institutionalization, QMPs are coherently fitted with the main organizational strategy and they have become an integrated QMPs for the entire organization, without remained as isolated quality practices which are narrowly termed as quality tools and techniques.