A method of automatic determination of a descent and approach profile for an aircraft is based on a backward computation of propagation of a state of the aircraft along segments S(i) from a backward computation start point to the start point DECEL of onset of the deceleration of the aircraft. The method of automatic determination comprises for each segment S(i) a step of determining an optimal speed VOPT(i) of the aircraft over the range of speeds of the next aerodynamic configuration C(j+1) to be implemented as a function of a predetermined deceleration strategy and/or of predetermined constraints inherent in the flight procedure or introduced by the pilot in his flight plan.