Abstract. This study determined the extent of the school heads' instructional leadership practices in the Division of Lanao del Sur II during the school year 2020-2021. The instructional leadership practices comprise vision, mission, and culture building; improvement of instructional practice; and management of people and processes. It also determined the level of teaching effectiveness of the public elementary school teachers in the domains of curriculum, learning environment, and diversity of learners, planning, assessing, and reporting, and personal growth and professional development. The relationship between school heads' instructional leadership practices and teachers' teaching effectiveness was also tested. A descriptive-correlational quantitative research design using two sets of questionnaires to gather the data. The questionnaire on instructional leadership practices was adopted from the Center for Educational Leadership Framework (2014). The second set was on teacher effectiveness, based on the Individual Performance Commitment and Review Form (IPCRF). The participants were the one hundred (100) public elementary teachers. The data were analyzed using the mean, standard deviation, and Pearson-r correlation. The findings revealed that the school heads often practice instructional leadership. The teacher effectiveness of the public elementary school teachers was very satisfactory. Also, there was a significant relationship between the instructional leadership practices of school heads and the teacher effectiveness of the public elementary school teachers.