Instrumented rolling bearing device of the type including a non-rotating race, a rotating race, at least one row of rolling elements arranged between two raceways of the rotating and non-rotating races, and an assembly for detecting rotation parameters including a non-rotating sensor assembly and a rotating encoder, and an elastic member intended for axially prestressing the rolling bearing, retained axially on the sensor, the elastic member being of annular shape and having a diameter smaller than or equal to that of the outer race of the bearing, the elastic member including a supporting surface designed to be in contact with an element outside the bearing device in order to exert, directly or indirectly, by reaction, an axial force on the non-rotating race in a direction opposite to the detection assembly.