ver the past few years, an increasing number of European pediatricians, particularly primary care pediatricians, are facing the growing threat of vaccine hesitancy and refusal, a sort of a “cultural epidemic,” which seems to progressively affect the families of children under their care. In several communities, a growing number of individuals are delaying or refusing available recommended and/or mandatory vaccinations for themselves and their children. Furthermore, vaccination is increasingly perceived as unsafe and unnecessary by a rising number of parents, although it has been widely proven and recognized to be one of the greatest, safest, and most successful public healthmeasures ever adopted.The aim of the article is to describe vaccine hesitancy and refusal in an effort to further raise the awareness of pediatricians on this potential threat for their communities, and, in particular, for children under their care. Definition and Effects of V