Competency-Based Medical Education (CBME) represents a major transformation in medical education from a predominantly teacher-centred, time-based, and knowledge-oriented system to a learner-centred, outcome-based, and competency-driven approach. In India, the implementation of the Competency-Based Undergraduate Curriculum has increased the need for institutional mechanisms capable of supporting curriculum planning, faculty development, innovative teaching-learning methods, competency-based assessment, educational research, and continuous quality improvement. The Medical Education Unit (MEU) serves as an important academic resource and institutional support system for facilitating these activities. The role of the MEU has expanded beyond conducting isolated faculty development workshops to providing continuous guidance for curriculum implementation, promoting integration, supporting early clinical exposure, facilitating self-directed learning, strengthening skills-based education, improving assessment practices, and encouraging educational scholarship. This review examines the evolving role of MEUs in the implementation and sustainability of CBME in Indian medical colleges. The article discusses the contribution of MEUs to faculty capacity building, curriculum planning, competency mapping, teaching-learning innovations, assessment reform, student support, educational research, and quality assurance. It also highlights the challenges encountered by MEUs, including inadequate infrastructure, shortage of trained personnel, limited protected time, resistance to educational change, variable institutional support, and insufficient longitudinal evaluation of faculty development programmes. Evidence indicates that successful implementation of CBME requires faculty development to be continuous, context-specific, experiential, and supported by feedback rather than limited to one-time workshops. The MEU should therefore function as a permanent academic and quality-improvement body integrated with institutional leadership, curriculum committees, departments, and clinical services. Strengthening MEUs through trained personnel, adequate resources, protected time, institutional authority, educational technology, and outcome-based evaluation can enhance the quality and sustainability of CBME implementation in India.