Recent years have witnessed an explosion of interest into the phenomenon of stalking and obsessive relational intrusion (ORI). A vast quantity of multidisciplinary research literature in this field has flooded professional and academic journals and the popular media. The authors review this literature in an effort to gauge the progress of knowledge in this area and ensure that future research stays on the best course for enhanced knowledge. The authors begin by reviewing the societal construct and the criminalization of stalking, noting that the media has romanticized the phenomenon of stalking and created an archetype of the typical stalker. During the 1990’s, as legislative efforts began to criminalize stalking behaviors, the view of stalking evolved into an interpersonal and relational problem. Research into the process of stalking revealed that it emerges out of the remnants of an established relationship, whether the relationship is intimate or merely of the acquaintance variety. One line of research in the late 1990’s began characterizing most types of stalking behavior as a form of obsessive relational intrusion (ORI). ORI is best understood as an invasion of a person's privacy by someone who desires or presumes an intimate relationship with the target of the stalking behavior. The literature regarding the incidence of stalking and characteristics of stalkers is reviewed, including motives for stalking and the effects of stalking on victims. Next, the authors look at theories that have emerged to explain this phenomenon, including routine activities theory, attachment theory, and linking and obsessive rumination theory. The authors conclude that collectively, the multidisciplinary research has contributed to a growing understanding of the etiology of stalking and its impact on the victim and the perpetrator. The development of more powerful and precise theories regarding stalking and ORI will lead to significant and needed improvements in the prevention, intervention, and treatment of perpetrators and victims. References