This chapter discusses the issues and challenges in the design of mobile ad hoc network (MANET) routing protocols and reviews routing protocols for MANETs. It describes various routing approaches for MANETs and compares traditional routing protocols for MANETs. The chapter discusses the impact of routing protocols on Wireless local area network performance. There are a number of challenging issues that need to be considered when designing MANET routing protocols. The MANET network topology changes dynamically as a result of node mobility, causing sessions of transferring packets to suffer from interference, leading to frequent path breaks. MANET routing protocols have distinguishing characteristics in the way they exchange information and establish communications. The main function of MANET routing protocols is to establish and enable transfer of data packets from a source to a destination node. The quality of service should be considered for all data traffic requesting communication in MANETs.