Vaccine hesitancy is a term used to refer to a series of attitudes ranging from reluctance to undergo vaccination to blatant refusal. In the context of the current pandemic, vaccine hesitancy is viewed as one of the ten major threats to public health. This narrative review, based on analysis of the most important literature reports on this topic, aims to illustrate the dimensions of vaccine hesitancy and the numerous sociodemographic and individual determinants involved, with particular reference to psychopathology, a somewhat neglected, but potentially relevant factor.