This study examined the instruction of Social Studies in the Kto12 Senior High School of Zone II, Department of Education (DepEd), Division of Zambales specifically assessing the three Knowledge Domains such as the Content Knowledge, Pedagogical Knowledge and Technological Knowledge. The respondents of the research study are the Senior High School Social Studies (Araling Panlipunan) teachers from Zone 2, Division of Zambales. The study was conducted during the third quarter of the school year 2018-2019. The statistical treatment of this study utilized descriptive statistical tools such as percentage and mean and ANOVA was used as inferential statistics. Based on the findings, the researcher concluded that the Senior High Social Studies teacher-respondents are female, in their early adulthood, Teacher I, holders of Bachelor Degree with Master’s units, quite new in the teaching profession and have attended seminars primarily on Teaching Pedagogy. The teachers have a very high extent of Knowledge on the domains Content Knowledge, Pedagogical Knowledge and Technological Knowledge. Moreover, results revealed a no significant difference on the level of teachers’ Content Knowledge, Pedagogical Knowledge and Technological Knowledge when attributed to respondents’ age, sex, field of specialization, highest educational attainment, academic position and years of teaching. However, there is significant difference when attributed to respondents’ number and types of seminars attended.