A method for the three-dimensional representation of the trajectory of an aircraft in flight implemented in a navigation system of an aircraft is provided. The flight plan of the aircraft comprises imposed georeferenced trajectories and predicted non-georeferenced trajectories. When the trajectory of the aircraft is dependent on a non-georeferenced flight setpoint, the three-dimensional representation method is an iterative process comprising the following steps: computing a predicted trajectory arising from at least one computed trajectory extending over a determined distance or duration; computing a smoothed trajectory from the predicted trajectory in order to obtain a resulting trajectory; computing a displayed trajectory, the trajectory being equal to the resulting trajectory corrected for constant deviations or deviations depending on the application of setpoints from the flight director; and displaying the displayed trajectory.