The study addresses teacher initiative as a measurable indicator of continuous professional development (CPD) effectiveness in the context of global educational transformations, where CPD has become a
strategic priority for ensuring educational quality and adaptability to change. The research aims to conceptualize teacher initiative as reflecting professional maturity, autonomy, and readiness for innovation. Methodology and Methods. This theoretical and analytical study employs content analysis, comparative analysis, and systematization methods to analyze international frameworks (CPD, OECD, UNESCO), educational policies, and empirical research. The research develops an evaluation algorithm for assessing educational initiatives implemented by teachers through systematic examination of existing literature and policy documents. Results. The study establishes that teacher initiative, demonstrated through development and implementation of original methodologies, participation in professional communities, and project-based activities, contributes to both individual professional growth and institutional advancement. An evaluation model integrating quantitative and qualitative criteria was developed, emphasizing the importance of motivation, creativity, and reflection in teachers’ developmental trajectory. The research identifies key components of teacher initiative and their measurable indicators for CPD assessment. Scientific novelty. The research provides theoretical conceptualization of teacher initiative as a core measurable indicator of CPD effectiveness, offering a comprehensive framework that bridges international standards with practical evaluation approaches and establishing the theoretical foundation for integrating initiative assessment into professional development systems. Practical significance. The findings support integration of initiative as a core element in teacher evaluation and professional growth systems, providing educational administrators and policymakers with evidence-based tools for assessing and promoting teacher professional development effectiveness in contemporary educational contexts.