The object of the present invention is an axillary support device (1) for a handicapped user of a common shower stall provided with at least one flat wall, substantially constituted by a pair of transverse arms (2, 3) fixed to the flat wall of the shower stall by means of a pair of vertical supports (4, 5) firmly anchored to said wall. Said transverse arms (2, 3) are arranged in a manner so as to be substantially perpendicular, in the longitudinal direction thereof, to the wall to which they are fixed; such arms (2, 3) are shaped in a manner so as to have one end (6, 7) bent upward, one end constrained (8, 9) to the vertical supports (4, 5) and they are provided with a covering made of soft and impermeable material. The vertical position and the horizontal position of said transverse arms (2, 3) can be adjusted, the latter being translatable along said vertical supports (4, 5) and lockable in pre-established positions. The device (1) also comprises a retention band (10) adapted to support the user and housed in the bent end (6) of a first (2) of said transverse arms, extractable therefrom, and reversibly constrainable to the bent end (7) of the second (3) of said transverse arms, in a manner so as to be arranged transversely to said arms.