This book constitutes the refereed proceedings of the Second International Conference on Ad-Hoc Networks and Wireless, ADHOC-NOW 2003, held in Montreal, Canada in October 2003. The 23 revised full papers and 4 revised short papers presented were carefully reviewed and selected from 42 submissions. All current aspects of ad-hoc networking, mobile, wireless, and cooperating communication systems are addressed including network architectures, access control and discovery, multicasting protocols, performance, quality of service, QoS, routing protocols, scalability, security, and self-configuration.