Wire rod of steel, produced by a hot rolling process, is cooled on a conveyor by action of fans sited under it. Mechanical properties of rod depend on chemical composition of steel and cooling rate experimented by the product. A mathematical model is developed in order to predict the thermal and metallurgical evolution of the steel rod on the conveyor. Convection and radiation losses are considered and the influence of the laying head is also discussed. Simulation results are compared with experimental measures obtained by an optical pyrometer in a real industrial process. Several product diameters and fan configurations are analyzed. Conclusions about the good accuracy of the model are shown. Thanks to the short computational time that the developed tool takes to predict the temperature of the wire rod along the conveyor, the tool can be potentially used in an on-line control system for the cooling process of wire rods.