Stalking and harassment both involve any repeated behaviour that would cause alarm, distress or fear of violence in a victim. Common stalking or harassment behaviours include unwanted contact online or in person, following a victim, and interfering with property. Stalking is characterised by a perpetrator’s fixation or obsession and can have long-term psychological and social effects on a victim. Stalking also has the potential to escalate to other crimes, such as sexual assault or murder. This POSTnote describes stalking and harassment before presenting evidence on the effectiveness of approaches to identifying, preventing and prosecuting these crimes.