Abstract: A variable infusion device for administering liquids parenterally to a patient is formed of inexpensive plastic members. The device includes an elongated passage defined between two members of the device which are bonded to one another. A third member is movable relative to the first and second members to change the length of the elongated passage through which liquid flows thereby changing the flow rate of the liquid through the device. The liquid flow rates to the patient can be incrementally adjusted over a wide range of flow rates. Settings also include a low flow rate for merely keeping the patient's vein open.