A walk assistance device capable of transmitting a force generated by a leg link to a user's trunk via a load transmit portion, wherein the leg link includes an upper first link portion connected to the load transmit portion via a first joint portion, a lower second link portion connected to a foot attachment portion via a second joint portion, a middle third joint portion connecting the first link portion to the second link portion such that a distance between the first joint portion and the second joint portion is variable, and a driving source that drives the third joint portion. The moment of inertia around the first joint portion of the leg link is reduced to decrease a load on the user's leg in walking. The driving source is disposed above the third joint portion of the first link portion so that the center-of-gravity of the entire leg link is located above the third joint portion. In the case where the driving source includes an electric motor and a reduction gear, the electric motor is disposed above the reduction gear.