This research investigates the "Effectiveness of Instructional Modular Approach on Enhancing Science Teaching Competency among Prospective Teachers" through an experimental method employing a single-group pre-test treatment post-test design. The study focuses on 27 prospective teachers enrolled in the physical science teacher training program at Al-Ameen College of Education, Somasipadi, Tiruvannamalai, Tamil Nadu, India. The three-month experiment, centered on three units of Pedagogy of Physical Science – I, utilizes a Science Teaching Competency Scale as the research tool. The study's objectives encompass assessing baseline science teaching competency, implementing the instructional modular approach, comparing pre- and post-assessment scores, and analyzing specific indicators of the approach's effectiveness. The research applies both parametric and non-parametric statistical analyses. Major findings underscore a significant enhancement in science teaching competency following the Instructional Modular Approach, reflected in increased post-assessment mean scores. The approach positively influences content competency, pedagogical skills, practical laboratory skills, technology integration, and assessment and feedback competency. Notable improvements are observed in content and pedagogical skills, with nuanced variations in different competency dimensions. The findings reveal differential enhancements across competency aspects, emphasizing the varied impact of the Instructional Modular Approach. Proficiency improvements in laboratory skills and technology integration underscore the approach's effectiveness in fostering a comprehensive skill set among prospective teachers. Percentage score increases validate tangible growth in applied skills, particularly in practical laboratory skills and assessment/feedback competencies. Statistical analyses, including correlation coefficients and 't' values robustly support the findings, indicating a significant difference between pre- and post-assessment scores. The study provides comprehensive insights into nuanced enhancements across various dimensions, confirming the Instructional Modular Approach's efficacy in shaping proficient and well-rounded science educators. The abstract concludes by highlighting the collective findings' validation of the approach's substantial impact on improving diverse teaching competencies, offering crucial insights for educational practices and teacher training programs.