In today's society, human cannibalism is extremely rare and represents an unthinkable act of violence. Scientific literature on the topic is sparse due to significant methodological problems, such as collecting enough data and generating unbiased analyses. The purpose of this article is to illustrate some psychodynamic aspects of cannibalism. After a review of the literature, we will present and compare five cannibalistic patients hospitalized in the Henri Colin secure unit (Villejuif, France). The patients described fall into two subgroups, suffering either from severe schizophrenia or from a mixed personality disorder with sadistic and psychopathic features associated with paraphilia. For the schizophrenia group, cannibalism is a self‐defense reaction to a perceived threat of destruction: survival depends on the annihilation or assimilation of the other. For the mixed personality disorder group, ego and narcissism are the central issue with a desire to overcome deep‐rooted frustrations by means of an extraordinary act.