Extracurricular activities comprise complementary training of medical students, contributing to professional and personal development through new experiences and learning. The aim of this study was to perform a narrative review on extracurricular activities analyzing characteristics, contributions, contradictions and challenges inherent to their practice in the context of medical education. The bibliographic review was developed from September 2016 to March 2017, referring to the PUBMED, SCIELO and LILACS databases, due to their importance as open sources of national, regional and global scientific literature, as well as Official documents and academic thesis that are unique and important to this study. The articles present the relevance of these activities for the professional formation in medicine, evidencing besides the cognitive benefit, the development of social conscience, practical and scientific abilities, as well as autonomy and proactivity. The literature confirms that complementary activities are inseparable from official curricular training. Through the analysis of this literature, it was observed that extracurricular activities influence various aspects of medical students, promoting the development of different skills, in the technical, social and humanistic spheres. However, when carried out in an excessive manner or at inappropriate times of graduation, they may damage the training process of these students.