An improved device for simple and reliable control of flow through a medical infusion line, one end of the medical infusion line having a fluid conveying pump provided on it and the other end assigned to a patient, the infusion line forming a main flow path from the fluid conveying pump to the patient-side end. Fluid is conveyed along the main flow path through the infusion line by means of the fluid conveying pump. At least a part of the fluid is introduced, along a measurement flow path branching off from the main flow path at a branching point, from the infusion line into a measurement reservoir connected to the infusion line. The infusion line includes a fluid restrictor between the fluid conveying pump and the branching point, and the main flow path as viewed in direction of the flow is interrupted after the branching point of the measurement flow path for filling the measurement reservoir by the pressure of the fluid conveying pump. The fluid in the measurement reservoir is detected.
