Mobile Ad Hoc Networks (MANETs) are the infrastructure less networks. In MANETs due to node’s mobility there is frequent change of topology and nodes are provided with limited energy sources. Due to these reasons nodes may behave selfishly means they may deny forwarding other nodes’ packets in order to save their energy. Hence it pivotal to compute the nodes’ trust in MANETs for establishing reliable and secure communication paths. In MANETs, low trustworthiness of routes can significantly impact network performance. Therefore, it is strongly advisable to incorporate the trustworthiness evaluation of a node when considering it as an intermediate node. In this paper an Eigen Vector based Trust Model (EVTM) is proposed for ensuring QoS in establishing routing paths between source and destination. The proposed method constructs the global trust matrix and is used to compute the dominant eigen trust vector. It ranks the each intermediate node between source and destination based on node’s fitness degree. Through experiments conducted in the ns-2 simulator, the method demonstrates superior performance across various metrics, including throughput, packet delivery ratio, packet delay, energy consumption, and packet drop. Notably, its consistent high performance, irrespective of the number of mobile nodes, underscores the effectiveness and scalability of the Eigen-based trust model in fostering trustworthy routing paths in MANETs.