Congestion is the primary reason for packet drop and delay in the mobile ad hoc networks. In this paper, a new routing protocol called Congestion-aware Fibonacci Multipath Load Balancing (Congestion-aware FMLB) routing protocol has been proposed that finds multiple node-disjoint paths between source and destination nodes, sorts them in increasing order of round-trip time of route request and route reply packets and distributes the data packets over these paths using the Fibonacci sequence numbers. The route that requires a little round-trip time, is used more frequently than the other paths. The performance comparison is performed for the proposed routing protocol with respect to Ad Hoc On-demand Distance Vector (AODV), Linear Multiple-path routing protocol (Linear) and FMLB routing protocols using GloMoSim Simulator 2.03. The results show that the Congestion-aware FMLB routing protocol has achieved a better packet delivery ratio, up to 141 % as compared to AODV, 109 % as compared to Linear and up to 65 % over the FMLB routing protocols. The results also show the improvement of end–end delay and normalized MAC overhead of the proposed routing protocols with respect to existing routing protocols.