Stalking is a frequently reported crime. It has a strong impact on the lives and mental health of the victims. It is perpetrated by persons who often suffer from mental disorders. This paper is an overview on the subject. It encompasses the various definitions of stalking, a number of classifications or sub-divisions of the phenomenon according to different approaches, a description of the psychopathology of the stalker, the psychological effect of the stalking on the victim, ways of evaluating and managing the phenomenon both in the victims and in the perpetrators, prevention of stalking, and also relevant bibliography. In addition, the paper includes an Appendix containing case series (clinical vignettes which include diagnosis, medical and legal interventions and outcome).