Schools must consciously seek principals who are instructional leaders. Principals who are comfortable with providing instructional support to teachers are likely to have been good teachers themselves (Glanz 2006). This descriptive method of research assessed the roles of Southeast Asian school managers as instructional leaders in the four domains of teaching responsibilities and explored relationships among the variables of the study namely: planning and preparation, the classroom environment, instruction, and professional responsibilities. The T-test determined the differences between the male and the female and between the Filipinos and the Non-Filipinos respondents which resulted to non-significant differences between neither of the two groups. The F-test was used to determine the significant relationships among the four domains of teaching responsibilities which established significant relationships between three pairs of domains. This research concluded that the SEA school managers are very comfortable with their level in working with teachers on content and pedagogical knowledge, knowledge of students and resources, ability to select instructional goals, and the degree to which they help teachers assess learning as well as the degree to which they encourage and create an environment of respect and caring and establish a culture for learning related to many aspects of classroom environment. Keywords - Southeast Asian School Managers, Instructional leadership, domains of teaching responsibilities, planning and preparation, classroom environment, instruction, professional responsibilities.