Crises affect schools across the country every day. While natural hazards such as tornadoes, floods, hurricanes, and earthquakes may be thought of more commonly as emergencies, schools are also at risk from other hazards such as school violence, infectious disease, and terrorist threats. Through the vulnerability assessment process, schools can take steps to prevent, mitigate, and lessen the potential impact of these risks by developing customized district and school emergency management plans in collaboration with community partners. Vulnerability assessments are integral to, rather than separate from, the ongoing emergency management activities of school districts and schools. This guide is intended to be a companion piece to "Practical Information on Crisis Planning: A Guide for Schools and Communities", originally published by the U.S. Department of Education in 2003 as a guide for schools and districts to prepare for a variety of crises. This guide emphasizes a valuable part of emergency management planning--ongoing vulnerability assessment--and is intended to assist schools with the implementation of an effective vulnerability assessment process, to include choosing an appropriate vulnerability assessment tool. Vulnerability assessment tools may vary from one school site to another, depending on variables such as: location, environment, size, and structure, and even student population and school culture. For example, schools may be located in urban or rural environments, may have limited or greater resources, or may have specific populations with their own unique needs. As a result, vulnerability assessments must be customized on an individual district and school basis, taking all of these factors into consideration. This guide is intended to describe the key elements to be considered when selecting an assessment tool appropriate for school environments and provide guidance for conducting an assessment that will inform school emergency management activities. Appendices include: (1) Additional Resources; (2) Vulnerability Assessment Focus Group Participants; (3) State Policy Requirements for K-12 School Safety and Security Assessments; and (4) Assessment Example. (Contains 1 figure, 1 table and 5 footnotes.) [For the companion report, "Practical Information on Crisis Planning: A Guide For Schools and Communities", see ED.]