In this study, the researcher sought to determine the relationship of school learning action cell (SLAC) practices on teachers professionalism and school performance in the elementary school of Peete, Laguna, and use the result as basis for developing school improvement plan. It was anchored on Social Learning Theory, Experiential Learning Theory and Transformative Learning Theory. The study followed the procedures of descriptive research method. A total of 100 teachers from public elementary schools in Paete Sub-Office were asked to answer the research questions.  It was found that the extent of relationship between SLAC practices with regards to assessment of teachers needs, coaching and mentoring, teaching and learning process, evaluation and feedback is to a very great extent the level of professional development with regards to assessment content and pedagogy, instructional delivery, assessment and evaluation, research and innovation, ethics and professionalism is very high and the level of school performance relative to Office Performance and Commitment Review Form (OPCRF) is very high. also the level of school performance relative to assessment result is fairly satisfactory However, with regards to SBM, school performance is only better. Thus, this study can help create school improvement plan, that can help elevate SBM levels and performance. Based on the results gathered from the study, the following are being recommended: School heads may continue to prioritize assessing teachers needs, so that they can craft fitted plans and seminars related to the professional growth of the teachers. Teachers can use self-efficacy and feedbacks from the learners for them to be able to assess what are the learners needs that they need to provide and enhancement on their teaching and learning delivery. Future researcher may create professional development plan that can fill the gaps on the professional development of the teachers. The study can be also conducted in other school and locale.