Abstract: Background and Objective: In Mobile Ad Hoc Network (MANET) existing misbehavior detection systems rarely consider both MAC and network layer misbehaviors. Hence the main objective of this work was to develop misbehavior detection and defense techniques for both MAC layer and network layer attacks. Materials and Methods: This paper proposed a cross-layer based misbehavior detection and defense technique (CLMDD) for MANET. Ant Colony Optimization (ACO) technique was applied to select reliable monitoring nodes which detected the misbehaving nodes. Then in receiver detection module, back off cheating was analyzed. In audit module, greedy nodes were detected which performs the Media Access Control (MAC) layer misbehaviors. Results: The proposed CLMDD technique was simulated in NS2 and compared with the Audit-based Misbehaviour Detection (AMD) technique. By simulation results, it had been shown that CLMDD attained reduced packet drop, energy consumption and normalized overhead when compared to AMD technique. Conclusion: It can be concluded that CLMDD had been considered as the best approach for detecting and defending the misbehavior attacks in MANET.