Energy consumption and security are two important aspects of Mobile Ad Hoc Networks (MANETs). In MANET, application security can be provided using trust management, key management, firewalls and intrusion detection. Moreover, it is often necessary to communicate secret information in military applications where urgent and reliable communication is more important. However, most of the existing routing algorithms do not focus on the energy and security aspects while routing. Since energy and security are important criteria for reliable communication in MANET, it is essential to consider the energy and security aspects in routing algorithms. The prevention of security attacks on routing protocols and cluster based routing automatically reduces the energy consumption. Hence, we propose a new secured routing protocol called Cluster based Energy Efficient Secure Routing Algorithm (CEESRA) in this paper which is energy efficient and uses cluster based routing in which the trust scores on nodes are used to detect the intruders effectively. This routing algorithm reduces the Denial of Service attacks more efficiently by using intelligent agents for effective decision making in routing. From the experiments conducted with this trust based secured routing algorithm, it has been observed that this proposed routing algorithm not only enhances the security but also reduces the energy consumption and routing delay. © 2017, Springer Science+Business Media New York.