A fragrance diffuser device for motor vehicle interiors, of the type comprising an elongated support body (1), a refill (3) of a fragrance-impregnated plastic material fixed to a fastening base of said support body (1), and an elastic clamp (2) to hook the diffuser onto a motor vehicle ventilation system grid. Said fastening base consists of a rib (4) longitudinally extending for at least part of said support body (1) length and retaining by friction said refill (3) of a fragrance-impregnated plastic material which at least partially surrounds said rib (4).
