The invention relates to a method and a device for regulating an ultrafiltration process in a dialysis treatment in which blood to be ultrafiltered flows through a blood chamber (110) of a dialyzer (113) in an extracorporeal blood circuit (109), said dialyzer being separated into the blood chamber (110) and a dialysis fluid chamber (108) by a semipermeable membrane (111), and the dialysis fluid flows through the dialysis fluid chamber (108) of the dialyzer (113) in a dialysis fluid circuit (109). The device has a blood pump (115) for controlling a blood flow in the extracorporeal blood circuit (112), a dialysis fluid pump (107) for controlling a dialysis fluid flow in the dialysis fluid circuit (109) upstream or downstream of the dialyzer, a throttle (117) for controlling the dialysis fluid flow upstream or downstream of the dialyzer, a balancing device (104) for establishing a fluid balance in the dialysis fluid circuit between a feed stream (106) and a discharge (105) of the dialysis fluid chamber (113) as a measurement for the ultrafiltration, and a regulating unit (101) for regulating the blood pump (115), the throttle (117) and/or the dialysis fluid pump (107). The pump or the throttle (117) is regulated such that a specified ultrafiltration is achieved.