This study investigates the impact of professional development (PD) on the professional efficiency of teacher educators in New Delhi, an area characterized by its diverse educational landscape and varying institutional contexts. Utilizing a mixed-methods approach, the research collected data from 150 teacher educators across various institutions through comprehensive surveys and in-depth interviews with a subset of 30 participants. The study aimed to identify how different PD programs influence teaching practices and overall professional growth. The results indicate a positive correlation between sustained, structured PD programs and significant improvements in professional efficiency. Key areas of improvement included lesson planning, instructional strategies, classroom management, and student assessment techniques. Quantitative data demonstrated marked increases in these areas post-PD participation, while qualitative insights revealed enhanced confidence, better classroom dynamics, and increased student engagement among educators. The findings underscore the importance of ongoing, relevant, and collaborative PD programs tailored to the specific needs of teacher educators. In-service training programs were found to be less effective due to their lack of practical relevance and follow-up support, whereas knowledge-in-practice models, which focus on experiential learning and real-world application, proved to be the most effective. This study highlights the necessity for educational institutions and policymakers to prioritize and invest in effective PD programs, providing adequate resources and support to ensure sustained professional growth. These insights offer valuable recommendations for designing PD initiatives that can significantly enhance the quality of teacher education and, consequently, overall educational outcomes