A method manages energy of a power unit of a hybrid vehicle. The power unit includes at least one internal combustion engine and an electric drive machine, coupled to wheels of the vehicle by a transmission with discrete ratios. The method includes minimizing, at each operating point of the energy, an energy criterion linked to a sum of consumption of the internal combustion engine and an electrical consumption of the electrical machine multiplied by an equivalence factor weighting a supply of energy from the internal combustion engine and a supply of energy of electrical origin. The minimized criterion is a mixed criterion which is a sum of an energy criterion and a discomfort criterion linked to management of kinematic modes of the transmission.