The study is a descriptive analysis of the ‘Affection Levels of Educational Facilities on the Instructional Function of Teachers’. The respondents of the study were the public elementary school teachers in Basilan Schools Division, Autonomous Region for Muslim Mindanao (ARMM). The study covered 9 central, and 9 non-central public elementary schools. A stratified random sampling was adopted in this study. A two - part survey questionnaire was used. One part of the instrument drew information about the demographic profile of the public elementary school teachers. Part two of the questionnaire determined the affection and adequacy levels of the educational facilities in Public Elementary Schools, as perceived by the public elementary schools teachers, in terms of physical features, indoor environment, equipment and utilities, media and technology, and safety and security features. The findings revealed that, the educational facilities in public elementary schools in the Basilan, moderately affect the instructional function of the teachers. The Equipment and Utilities elements affect the instructional function of teachers to the greatest extent. The Safety & Security Features affect the instructional function of teachers to the least extent.