Curriculum viability, teaching competence, and effective instruction are paramount in advancing Philippine education. This study examined the combined influence of curriculum viability and teaching competencies on effective instruction among teachers in the Davao region. Three selected schools in the Davao region were involved, and 100 teachers responded to the survey. The research design utilized a quantitative-nonexperimental approach with descriptive-correlational and regression analysis. The results indicated a high level of curriculum viability, suggesting that the implemented K to 12 curriculum in the Davao region is well-designed, aligned with quality standards, and provides relevant and challenging learning targets. Additionally, the study revealed a high level of teaching competencies among the teachers, indicating that they possess the necessary skills, knowledge, and beliefs to deliver effective instruction and create a positive learning environment. Furthermore, the findings demonstrated that teachers perceived effective instruction as high. They effectively established a positive learning environment, set clear and shared outcomes, employed varied instructional methods and materials, fostered complex thinking and transfer, and provided practice and feedback. The regression analysis confirmed that curriculum viability and teaching competencies significantly influenced effective instruction. This highlights the importance of considering curriculum viability and promoting teacher competencies to enhance instructional practices. This study provides valuable insights into the combined influence of curriculum viability and teaching competencies on effective instruction among teachers in the Davao region. The findings underscore the significance of these factors in promoting quality education in the Philippines.