International research has established that stalking is a prevalent problem with serious and often life-threatening consequences for victims. Stalking is also a unique form of violence due to its nature and diversity, making it difficult for criminal justice and health professionals to establish which perpetrators and victims have the greatest need for services and protection. Risk assessment is one way to address these problems but few tools exist. This article describes the development of the Guidelines for Stalking Assessment and Management (SAM), the first risk assessment instrument designed specifically for the stalking situation. Preliminary data are presented, indicating that the SAM has promise for use by professionals working with stalkers and their victims. Results indicated that interrater reliabilities for the SAM risk factors and total scores range from fair to good, and the structural reliability of the SAM is sound. Moreover, the SAM showed good concurrent validity when compared with two other measures of violence propensity: the Psychopathy Checklist Screening Version (PCL:SV) and the Violence Risk Appraisal Guide (VRAG). Limitations of the study are discussed, especially those related to the difficulties inherent in file-based research, and suggestions for future research are offered. © 2011 John Wiley & Sons, Ltd.