The study aimed to determine the extent of school-based management and the extent of instructional task of public secondary school teachers. This study employed a non-experimental quantitative research design utilizing descriptive-correlation method. Validated questionnaire and Universal sampling procedure were utilized considering the minimal number of teachers in the research locale. One hundred twenty (120) public secondary school teachers were the respondents of the study. Using mean, Pearson-r, and regression analysis, the findings revealed that the extent of school-based management was extensive while the extent of instructional task of public secondary school teacher was also extensive. Moreover, the overall results disclosed that indicators for the school-based management were positively correlated to the instructional task of public secondary teachers. Further, results from the regression analysis revealed the following have a strong influence of school-based management on the instructional task of public secondary teachers: leadership and governance and curriculum and planning. On the other hand, accountability and continuous improvement and management of resources are not related to the instructional task of public secondary school teachers. It is recommended that teachers are prone to commit lapses on the school-based management, every school should devise an improved Developmental Plan on School-Based Management or enhance it if there is already a program to ensure that the school management is promptly addressed and given utmost attention.