A motorized wheelchair having right and left motorized rear wheels (1), and fixed front wheels (5) in which a plurality of rollers (6) rotatable in a direction orthogonal to an alignment direction of wheels are disposed therearound, comprises transmission rollers (11) to transmit the rotation of the rear wheels (1) to the front wheels (5) while being disposed at a transmission position between circumferential surfaces of front and rear wheels in order to easily perform the switching to the four-wheel drive as necessary, a roller supporting arm (12, 12A) for rotatably and oscillatingly supporting the transmission rollers (11) in the front-rear direction of the wheelchair, and transmission roller pressure-contact springs (16) for urging the roller supporting arm (12, 12A) in a direction of the transmission position so as to be pressure-contacted with the circumferential surfaces of the wheels at the transmission position. An operation lever (14) constrains the roller supporting arm (12, 12A) in an interlocking manner in the direction away from the transmission position when being at the regular position, and releases the constrains when the operation lever (14) being at the working position so as to allow the transmission rollers (11) to be disposed at the transmission position.
