In the past decades, the evolution of wireless technologies has brought significant changes in modern communication networks through its wireless extension of wired networks. Wireless communications offer organizations and users many benefits such as portability and flexibility, increased productivity, and lower installation costs. However, risks are inherent in any wireless network. As the technologies of next generation wireless networks are emerging, security has become a primary concern in order to provide dependable and secure communication between the wireless nodes in a hostile environment. The next generation wireless networks face many unique challenges in security such as open network architecture, shared wireless medium, limited resource constraints, and highly dynamic network topology. This special issue in Security and Communication Networks presents current research focusing on the standard or protocol related security, attacks and defense applications, security architecture and frameworks, and theories and methodologies in security in next generation wireless networks.