To find out the most appropriate learning theory for the ethics education of medical undergraduates.Two electronic databases were searched PubMed and Web of Science. We searched for published articles written in English without a time limit using the keywords: ethics education, medical undergraduates and learning theory. In the four-phased retrieval process, six full texts out of 133 citations were included in this review. Data were analyzed done by conventional content analysis.This systemic review revealed that reflection is the most effective pathway to develop ethical attributes and values of the physician. Social constructivist and experiential theory seem appropriate to form the basis for developing effective ethics curriculum.This review heightens the importance of learning theories for ethics education. It gives prompt evidence that reflection is the most suitable model for ethical education. Therefore, the educational theories and teaching activities that endorse reflective learning should be used for ethics education.