Abstract: In this paper, we propose an efficient routing algorithm, for mobile ad hoc networks, which we refer to as GZRP, a hybrid protocol that makes use of the ZRP scheme and the Global Positioning System (GPS). As opposed to the ZRP original scheme, our GZRP scheme consists of propagating the routing (query) messages only to the nodes that are further away from the query source. We discuss the algorithm, its implementation, and report on the performance of GZRP scheme. Our results indicate clearly that GZRP outperforms ZRP by reducing significantly the number of route query messages, and thereby increases the efficiency of the network load. Furthermore, we show that careful GPS screening angle is an important factor in the success of the GZRP ad hoc routing protocol.