This paper addresses the problem of coordinated path-following of networked autonomous vehicles with discrete- time periodic communications. The objective is to steer a group of autonomous vehicles along given spatial paths, while holding a desired inter-vehicle formation pattern. For a class of vehicles, we show how Lyapunov based techniques, graph theory, and results from networked systems can be brought together to yield a decentralized control structure where the dynamics of the cooperating vehicles and the constraints imposed by the topology of the inter-vehicle communications network are explicitly taken into account. Vehicle coordination is achieved by adjusting the speed of each vehicle along its path according to information exchanged periodically on the positions of a subset of the other vehicles, as determined by the communications topology adopted. Stability and convergence of the overall system are guaranteed and a criterion for selecting the coordination gains is presented.