The purpose of this workshop is to address concerns regarding security in mobile and wireless networks. These concerns are due to the increase in potential damage that can be done to these networks, from both traditional security threats that have not been adequately addressed by the very large-scale distributed networks now in place, and new security threats inadvertently created from the new services available in these networks. Although solutions to the traditional link-layer wireless communication security issues seem to be more or less available, modern network-focused security threats demand additional research efforts. In view of this, the workshop objective is to identify the critical issues in the discipline and to develop a consensus-based document that will provide a foundation for implementation and standardization as well as further research. This International Workshop on Research Challenges in Mobile and Wireless Networks Security and Privacy will be held in conjunction with the INFOCOM 2005 in Miami, Florida, 13 March 2005, so that top researchers and practitioners from various areas will present to discuss and analyze the pertinent issues.