Lean management with organizational commitment of employees is recognized to improve hospital service operations. This research explores the extent to which lean management practices are adopted by hospitals in Thailand. The purpose of this paper is to investigate lean practices and organizational commitment affecting operational performance in hospitals. Data was collected from the hospital implemented lean projects in Thailand. Questionnaire survey was used to collect the data. Factor analysis and multiple regression analysis were conducted to examine the relationship between lean practices, organizational commitment and operational performance. The results of this study highlight the importance of human resource management, a focus on patient flow and social capital as the critical resources of operational performance in healthcare setting. The result also provide practitioners with guidelines in implementing lean more efficiently and effectively for enhancing their capability and competitiveness.