This study was conducted to explore the element of skill mastery in the steward leadership practice of headteachers in elementary schools who have successfully strengthened the employees’ skills in asset and store control until the school has successfully achieved excellent audit reportss. This study is based on the Steward Leadership Practice Framework that was proposed by April, Peters, and Kukard in 2013. In this study, a total of seven study participants were selected, namely seven elementary school headteachers in public schools. This study uses a fully qualitative approach and the focus group discussion method as the main data collection method. The data obtained was analyzed using Nvivo 12. The findings show that headteachers’ practice in the mentoring category is to defend the employees’ rights and identify their background. Besides, in the category of personal mastery, the practices done by headteachers are to collaborate with mentors and respect abilities. Finally, for the risk-taking and experimenting category, the practice of tolerating mistakes was applied. These practices are done to ensure that the control of assets and stores under General Treasury Instructions 1.1 can be carried out effectively, thus all the asset and stock can be used safely by students in public elementary schools. Thus, the activities of acceptance rules, registration, asset labeling, asset use, asset inspection, stock calculation, stock inspection, store verification, and disposal of assets and low-value stock can be carried out properly and aligned to the correct procedures and laws. Researchers suggest that a follow-up study be carried out, focussing on other aspect of internal control involving study participants from secondary public schools or any other educational institutions that received excellent audit reports for comprehensive and deeper interpretation and understanding.