Abstract: An apparatus for peritoneal dialysis including a first vessel to contain dialysis fluid and a second vessel to contain spent dialysis fluid. The first and second vessels are connected through a conduit means with the abdominal cavity of a patient, and a pump is located in the conduit means between the first vessel and the abdominal cavity to pump dialysis fluid into the cavity, while a flow control means, such as a valve, is located in the conduit means between the abdominal cavity and the second vessel to control the flow of dialysis fluid being removed from the patient. A branch conduit interconnects the conduit means at a location between the first vessel and the abdominal cavity and the branch conduit is provided with a third overflow vessel located at a higher level than the abdominal cavity.