With concerns about medical errors, high operating cost, limited resources, and inefficient operations in hospitals, a variety of improvement initiatives have been adopted with the aim of alleviating all operating issues in healthcare service organizations. Lean management with organizational commitment of employees is recognized to improve hospital service operations. Lean strategy is one of the latest organizational innovations focusing on eliminating waste throughout all activities within the organization. Lean concepts were initially developed in manufacturing industry, where they were pioneered by Toyota Production System. Since then, the concepts have been widely applied by other manufacturing industries; including automotive industries, electronics industries, etc. Recently, the applications of lean strategy have diffused and effectively transferred to service sectors; particularly in healthcare services. Considering emerging economy countries, Thailand healthcare industry has dramatically been growing from national demands; demands from other countries in Southeast Asia, and medical tourism. With the aim of gaining higher competitive advantage, Thai healthcare service providers strived to improve their operational processes to ensure that they are efficiently operated with low cost and high quality, thereby enhancing customer satisfaction. Thai healthcare organizations started to aware of lean concepts and principles since 2008. In 2008, Asia Productivity Organization (APO) together with the Healthcare Accreditation Institute (Public Organization) initiated the pilot project called “Demonstration Project for Lean Application in Healthcare Industry” in five major Thai hospitals. Furthermore, the Healthcare Accreditation Institute of Thailand had set the theme for Hospital Accreditation for the year of 2009 as “Lean and Seamless Healthcare”. Later, additional six hospitals voluntarily applied to pilot lean project phase II to implement lean strategy as organizational innovation. Consequently, more hospitals tend to proceed with the same fashion. However, healthcare organizations seem to lack of awareness relevant to the impact of implementing this organizational innovation (lean practices) in to service organizations. By understanding the lean practices of which have impacts on operational performance, healthcare organization could determine whether or not to adopt the organizational innovation in their organizations as well as to provide appropriate learning mechanisms and necessary resources. Given that most previous literature has studied lean practices only in manufacturing organizations, bundles of lean practices have not been identified outside manufacturing. Similarly, the operational performance of manufacturing firms was well studied, but not for those of service firms.