In the near future, networks will be expected to support a wide range of real-time multimedia applications that are sensitive to certain Quality of service (QoS) constraints. Also, the need for mobility is one of today's important needs. One of the challenges in networks is to provide a routing protocol that is capable of offering a shortest path as well as maintaining the QoS demands in Mobile AdHoc Networks (MANETs) in which users have no base station to be used as a fixed reference for their position. The ultimate aim of this work is to develop and evaluate a new distributed QoS routing algorithm for MANETs based on Fano's method and the DSDV protocol, which we call Fano's Modified DSDV QoS routing Algorithm for MANETs (FDQA). We summarise the thesis contributions as follows: Firstly, we propose a distributed QoS constrained unicast routing algorithm for MANETs based on Fano's algorithm. Secondly, we modify the proposed algorithm to make the routing decision based upon the heading angle of the source and its neighbours. Finally, we define a "tilted distance" in our algorithm to decide whether the algorithm is moving in the right direction or not.