This dialysis-fluid supply system, which mixes a diluent and at least two drugs to generate a dialysis fluid, and outputs said dialysis fluid, is provided with: two tanks which mix the drugs and the diluent to generate the dialysis fluid, and store said dialysis fluid； a water supply device and a drug supply device which supply the diluent and the drugs to each of the tanks； mechanisms for outputting, to a dialysis device, the dialysis fluid stored in each of the tanks； and a control unit for controlling the driving of these. During output of the dialysis fluid from at least one of the tanks, the control unit sequentially switches the supply destination tank for the drugs and the diluent, and the dialysis-fluid output source tank, between the two tanks in order to generate the dialysis fluid in the other tank.
