This study targeted to explore the role of the school administration in minimizing the educational wastage in post basic schools in Sultanate of Oman, from the point of view of the schools' principals, their assistants and senior teachers. It also aimed to identify if there are significant differences among the responded related study variables. The study sample consists of (190) schools principals of post basic, their assistances and senior teachers, represented four educational areas in Oman. A questionnaire consists of (64) items was developed which divided in six domains: school administration, teacher professional development, students sustainable development, curriculum and learning activities implemented, school building supplement and management, and activate local society relationship. The questionnaire reliability Cronbach -alpha is (0.96). Means and standard deviation, t-test and Analysis of Variance (ANOVA) were used to analyze data. The main findings of the study showed that there are significant differences (0,05 = a) among the individuals' responses of the study sample related to " students sustainable development" due to the educational area in between Muscat & Dhofar in favor of headmasters in Dhofar region. There are significant differences (0,05 =a) among the individuals' responses in the first five domains of studies except the sixth one "activate local society relationship" due to gender in favor of female. Finally, the study result showed there are significant differences (0,05 =a) among the responses in the second domain" teacher professional development "due to experience in teaching in favor of (6-10) years of experience. Depending on the study result several recommendation were stated such as: further studies are required to investigate the educational wastage especially in the use of technology, and the wastages in stationary and school building and equipments.