The proliferation of online hate groups over the past few years has brought two main issues into focus. First, legal and political scholars have questioned the extent to which such hate speech should be regulated. Second, and perhaps more importantly, there is a great deal of concern about the effects of hate expressed online – specifically, if it incites violence and hostility between groups in the physical world. Understanding cyberhate therefore provides an important challenge for psychologists. Specifically, it is important to understand why online hate is so widespread and the content of online hate sites often so insulting and aggressive, given that the physical activities of hate groups are much more covert. This article attempts to provide a psychological perspective on the nature and purpose of online hate groups and their underlying motivations, their strategies, psychological theories and research that provide insight into disinhibited online behaviour, the actions being taken to combat cyberhate, and some challenges for future research.