Although not a new concept in itself, competency-based education has set the trend for the globally accepted standard norm for education and training of medical professionals including postgraduate education in radiation oncology. Societal needs demand from radiation oncologists that they be not only competent in the knowledge and skills relevant to their specific discipline, but that they also display competencies such as professionalism, scholarship, health advocacy, management/leadership, collaboration and communication. The realities of developing countries, in particular low and middle income countries (LMICs) set different priorities than in high income countries. A large proportion of cancer patients do not have access to adequate radiotherapy services. Resource constraints determine limitations in equipment, accessories, and dosimetry. Lower than standard staffing levels and limited quality education and training also contribute to substandard care and clinical outcomes. In this environment, the addition and assessment of competency-based elements to training programmes can be challenging. On the other hand, it is precisely in these countries, where competencies such as the ones listed above are highly needed in the radiation oncology profession. Implementation of competency-based medical education in the education of radiation oncologists in LMICs is both a need and a challenge. The available frameworks and competencies, despite being very relevant to the realities faced by radiation oncologists in LMICs, will still need to be adapted in order to ensure effective implementation at the national/regional level. Radiation oncologists need to employ effective change-management strategies to ensure that the changes which are introduced can remain sustainable within the context of national healthcare, education and political systems.