A walk assistance device capable of transmitting a force generated by a leg link (5) to a users trunk via a load transfer portion (1), wherein the leg link includes an upper first link portion (6) connected to the load transfer portion via a first joint portion (3), a lower second link portion (7) connected to a foot attachment portion (2) via a second joint portion (4), a middle third joint portion (8) which connects the first link portion to the second link portion in such a way that a distance between the first joint portion and the second joint portion is variable, and a driving source (9) which drives the third joint portion and wherein the moment of inertia around the first joint portion of the leg link is reduced to decrease a load on the users leg in walking. The driving source (9) is disposed higher than the third joint portion (8) of the first link portion, (6) so that the center-of-gravity of the entire leg link (5) is located higher than the third joint portion (8). In the case where the driving source (9) includes an electric motor (91) and a reduction gear (92), the electric motor (91) is disposed higher than the reduction gear (92).
