A wearable action-assistance device is provided that can be fitted to and worn by various wearers who have different body types and sizes. A wearable action-assistance device (10) has a hip frame (11) that is to be worn on the hips of a wearer, a lower limb frame (12) that is to be worn on lower limbs of the wearer, and drive portions (13R, 13L, 14R, 14L) that are provided on the lower limb frame (12) in correspondence with joints of the wearer. The lower limb frame (12) has variable shape portions (41L, 41R, 42L, 42R, 43L, 43R, 44L, 44R, 45L and 45R) that can cause a plurality of places including portions in the vicinity of the drive portions (13R, 13L, 14R, 14L) to bend to the left and right to adjust flexion angles thereof. By being able to bend a plurality of places on the lower limb frame (12) to the left and right, the shape of the lower limb frame (12) can be adjusted so as to fit the leg shapes of even knock-kneed or bowlegged wearers.
