The cure of an unsaturated polyester was studied by using experiments and a model of the process. Two kinds of experiment were conducted, one with the calorimetry in scanning mode for determining the kinetics of curve, the other with a rather large cylinder. The numerical model was constructed by taking into account the heat transferred by conduction through the resin, and convection at the surface, as well as the kinetics of heat generated by the cure reactions. The temperature-time histories in the middle of the cylinder obtained either from experiments or by calculation were compared, and found in good agreement, providing the accuracy of the values of the kinetic and thermal parameters.