A landing aid method and device for an aircraft including a unit for calculating automatically in a repetitive manner, during a final approach of the aircraft with a view to landing on a landing runway, using at least a ground speed of the aircraft, a height of the aircraft in relation to the ground, and a target vertical speed representing a vertical speed required on contact with the landing runway, a slope angle of a flight path allowing the aircraft to perform a flare, checking at least the target vertical speed on contact with the landing runway, and a unit for displaying automatically, on at least one screen of the flight deck of the aircraft, a first symbol illustrating the current slope angle of the aircraft and a second symbol illustrating the calculated slope angle.