MANET is a spontaneous system of mobile nodes where each node plays the role of router and mobile station. They can join or disconnect from the network any time and transfer packets in peer-to-peer mode or a multicast mode. Nodes are connected by way of wireless links and form a random topology graph. Network topology may change rapidly and erratically, so it can considerably affect packet routing in terms of network throughout, load and delay. Multiple hops can locate between diversity of node’s route as a consequence form the communication as expanded complexity. In this paper the performance of three well-known MANET routing protocols - Ad hoc On-demand Distance Vector (AODV), Dynamic Source Routing (DSR) and Optimized Link State Routing (OLSR) - has bees been investigated. Furthermore, all above mentioned protocols are compared based on three important performance metrics which are average end-to-end packet delay, network load as well as network throughput.