Method for estimating the electromagnetic torque of a permanent-magnet three-phase synchronous electric machine for an electric or hybrid motor vehicle, comprising steps of: - measuring the currents and voltages on the phases of the stator of the machine in a fixed three-phase reference system tied to the stator, - determining the currents and voltages (i αβ, v αβ) in a fixed two-phase reference system tied to the stator as a function of the current and voltage measurements in the three-phase reference system, - calculating a first estimate of the flux ( λ̂ αβ) of the machine by calculating the integral of the electromotive force, the electromotive force being calculated based on the voltages and currents expressed in the fixed two-phase reference system tied to the stator, - estimating the electromagnetic torque (T̂ e) based on the flux estimated by the first estimate, said method being characterized in that it comprises steps of: - determining the currents and voltages (i dq, v dq) in a rotating two-phase reference system tied to the rotor as a function of the currents and voltages (i αβ, v αβ) expressed in the fixed two-phase reference system and the position of the rotor (θ e) with respect to the stator, - calculating, in parallel, a second estimate of the flux of the machine ( λ̂ αβ) using the currents expressed in the rotating two-phase reference system tied to the rotor, said second flux estimate being corrected by introducing variables characterizing magnetic uncertainties of the machine, said variables being determined by an observer based on the stator currents and voltages (i dq, v dq) expressed in the rotating two-phase reference system tied to the rotor, - comparing the torque (T̂ e) estimated based on the flux estimated by the first estimate and a setpoint torque (T* e) and - resetting the initial conditions of the flux in line with the first estimate based on the flux estimated by the second estimate when the difference between the torque estimated based on the flux estimated by the first estimate and the setpoint torque exceeds a predefined threshold (ε). - measuring the currents and voltages on the phases of the stator of the machine in a fixed three-phase reference system tied to the stator, - determining the currents and voltages (i αβ, v αβ) in a fixed two-phase reference system tied to the stator as a function of the current and voltage measurements in the three-phase reference system, - calculating a first estimate of the flux ( λ̂ αβ) of the machine by calculating the integral of the electromotive force, the electromotive force being calculated based on the voltages and currents expressed in the fixed two-phase reference system tied to the stator, - estimating the electromagnetic torque (T̂ e) based on the flux estimated by the first estimate, - determining the currents and voltages (i dq, v dq) in a rotating two-phase reference system tied to the rotor as a function of the currents and voltages (i αβ, v αβ) expressed in the fixed two-phase reference system and the position of the rotor (θ e) with respect to the stator, - calculating, in parallel, a second estimate of the flux of the machine ( λ̂ αβ) using the currents expressed in the rotating two-phase reference system tied to the rotor, said second flux estimate being corrected by introducing variables characterizing magnetic uncertainties of the machine, said variables being determined by an observer based on the stator currents and voltages (i dq, v dq) expressed in the rotating two-phase reference system tied to the rotor, - comparing the torque (T̂ e) estimated based on the flux estimated by the first estimate and a setpoint torque (T* e) and - resetting the initial conditions of the flux in line with the first estimate based on the flux estimated by the second estimate when the difference between the torque estimated based on the flux estimated by the first estimate and the setpoint torque exceeds a predefined threshold (ε).