A recoil damping device for portable firearms, including a casing in which a recoil damping means is inserted; the damping means includes a fixed part, which is integral with the casing, and a movable part able to slide along a substantially axial direction inside the casing; the damping means is made of a material having a certain elastic hysteresis and includes a set of flexible members connecting the fixed part to the movable part; the flexible members have different stiffnesses.