Hybrid wireless networks, consisting of infrastructured and adhoc wireless networks have attracted attention of research community in the last years. An efficient routing protocol plays a key role in achieving high throughput in hybrid wireless networks. Nevertheless, the majority of proposed routing protocols don not employ all cellular and adhoc capabilities to increase overall performance. In addition, most of them do not take QoS requirements into consideration. In this thesis, a multipath on demand routing protocol for hybrid wireless networks with nodes equipped with single WiFi interface (IEEE 802.11) is presented. The WiFi interface enables nodes to communicate with both access points and mobile nodes through multihop paths. In addition, a distributed probing scheme is used to estimate end to end performance. Based on probing results, source nodes balance their traffics among available paths.Simulation results based on NS-2 simulator reveal that the proposed protocol has better packet delivery ratio compared to the previous well-known routing protocols. Keywords :Hybrid wireless networks, QoS, WiFi networks