Mobile ad hoc networks (MANETs) are characterized by multi-hop wireless connectivity, frequently changing network topology and the need for efficient dynamic routing protocols plays an important role. A variety of routing protocols targeted specifically at this environment have been developed and some performance simulations are made on numbers of routing protocols like Ad hoc On-Demand Distance Vector Routing (AODV), Dynamic Source Routing (DSR) and Location-Aided Routing (LAR). To the best of our knowledge, no published work is available in the literature, which compares as many criteria as we have done to evaluate the performance of the considered routing protocols. In this paper we perform extensive simulations using GloMoSim simulator considering 18 performance metrics. To determine the impact of network size on the performance of these protocols we considered two different scenarios, namely, 100 and 200 nodes, with rectangular area sizes 1500 × 1000 and 2000 × 1500 m2, respectively.