Purpose: Medical educators are central in ensuring future doctors have sufficient public health skills. Attitudes, norms, and perceived control about the significance of teaching a subject determines whether or not it is taught and how well. This qualitative study aims to explore medical educators’ perceptions about what factors influence their intention to teach public health in Indonesian undergraduate medical schools. Methods: Semi-structured interviews were conducted with eighteen medical educators from different Indonesian medical schools. Interviews were analyzed thematically using the Theory of Planned Behavior domains: attitudes, subjective norms, and perceived behavioral control. Results: Five subthemes emerged under these domains: attitudes (defining public health); subjective norms (room in the medical curricula; teaching and assessment); and perceived behaviour control (medical educator confidence; institutional support). Most participants had a limited understanding about the scope of public health. This coupled with an already overcrowded medical curriculum made it challenging for them to incorporate public health into the medical curriculum dominated by clinical and biomedical content. Although believing that public health is important, medical educators were reluctant to incorporate public health because they were not confident incorporating or assessing content. Conclusion: Strong institutional support is to improve public health quality and content in the medical curriculum. Including public health educators in discussions is critical.