Abstract: A method and device are provided for assisting in height holding in air navigation, consisting, for any point (M) of the image of the landscape flown over by the aircraft (A), located by its angle of elevation (.theta.-p) with respect to the speed vector V of the aircraft, and situated in a zone between a lower elevational limit (.theta..sub.1 -p) and an upper elevational limit (.theta..sub.2 -p), in the trajectory of the aircraft, in detecting a possible deviation between the angular speed .OMEGA. of movement of this point with respect to the aircraft, depending on the height (h,H) of subsequent crossing of this point by the aircraft, for identical piloting conditions, and an angular reference speed of movement (.OMEGA..sub.o) corresponding to a reference height (h.sub.o,H.sub.o) of subsequent crossing by the aircraft of a point having the same elevation (.theta.