A walking assist device having a load transmit portion, a leg link connected to the load transmit portion, and a driving source capable of driving the leg link in a direction to raise a seat member, so that at least a partial weight of a user may be supported by the leg link through the load transmit portion. An electric component to be used for controlling the driving source can be mounted on the walking assist device without degrading the compactness of the walking assist device. At least a part of the leg link is constituted of a cylindrical link member in which at least the electric component, such as a motor driver to be used for the control of the driving source, is partially housed. The walking assist device also includes a heat transfer member for absorbing the heat of the electric component by the cylindrical link member. The heat transfer member is thermally connected to a side plate of the cylindrical link member directed toward the side opposite to the leg of the user.