A navigation aid information display device of an aircraft and primary flight display for an aircraft are disclosed. In one aspect, the navigation aid information display system includes a display screen including at least one first display area configured to display a first altitude scale including graduations, the current altitude of the aircraft on the first scale, and set altitude value. The graduations of the first scale are distributed on an arc of a first disc including a first needle centered in the disc and the first needle is configured to indicate the current altitude on the first scale. The distribution of the graduations on the arc is nonlinear and symmetrical relative to a graduation corresponding to the set altitude value and defines extension graduations decreasing from the set altitude value.