Improved route reliability is one of the key parameter for successful dissemination of the multimedia and emergency messages in decentralized, highly dynamic Mobile Ad Hoc Networks (MANETs). In order to achieve this, an energy e cient optimized routing protocol is essential, as mobile nodes run on battery power. There is plethora of studies that emphasizes on route reliability and energy consumption by modifying the existing MANET reactive routing schemes. Most of these are based on shortest path with traditional single layer approach, allows only one or two node parameters for both relay node selection and optimal path. However, due to the nature of the MANETs, still several factors such as unnecessary ooding of control packets and intermittent connectivity among the nodes distress the battery power directly. Therefore, in this paper, an Ant colony optimization based energy aware cross layer routing protocol (AOERP) is presented. The proposed AOERP includes series of mechanisms: rstly, selection of an adaptive relay nodes based on high energy factor and neighbor node ratio at each node in the network to avoid dead nodes and secondly identifying a nest path among the selected relay nodes in the direction of destination using Ant Colony Optimization (ACO) method. These mechanisms make an attempt to improve the route reliability and in turn increases entire network lifetime to overcome the rerouting in the network by making use of multiple node parameters from lower three layers such as physical, MAC and network layers. The performance of the proposed AOERP protocol is carried out using Network Simulator Version 2.34 (NS-2.34) and compared over existing energy aware routing schemes.The simulation results show that the proposed AOERP outperforms in terms of reliability, energy factor, average end-to-end delay and percentage of dead nodes for different node density and node speeds.