The invention relates to a method of determining the angular position of a first rotor of a turbojet, the method consisting in: generating at least one vibration pulse during a rotation of the first rotor, each vibration pulse being generated when the first rotor passes through a given reference angular position; detecting the vibration generated thereby; obtaining (E30) the angular position at a given instant of a second rotor of the turbojet relative to the angular position that it occupied at a reference instant representative of detecting a vibration pulse, said second rotor being coupled in rotation with the first rotor and having a speed of rotation different from the speed of rotation thereof; and determining (E40) from the angular position of the second rotor, the angular position of the first rotor at said given instant.