The adoption of inquiry-based science instruction is a key objective of modern education, including the Philippine K to 12 curriculum. However, quantitative evidence on the actual teaching practices of Senior High School STEM teachers remains scarce. This study addresses this gap by employing the Science Instructional Practices Survey (SIPS) to assess the frequency of instructional practices among 30 STEM teachers in Davao City. Results show that traditional instruction and activation of prior knowledge were implemented most frequently, while student-centered practices like modeling and student-led investigation occurred less often. Teacher background variables—years of experience, educational attainment, and professional development hours—did not significantly predict the frequency of inquiry-based practices. The findings indicate that while foundational and analytical skills are addressed, the full implementation of student-driven, inquiry-based learning is not yet realized. The study recommends targeted professional development and systemic support to better align classroom practices with contemporary science education frameworks.