Abstract: An automated peritoneal dialysis machine is provided which is capable of selecting and changing the composition of dialysate delivered to a patient in the course of treatment to meet specific physiological needs. The apparatus includes means for metering solutions of osmotic agent, electrolytes and other desired dialysate components from separate solution containers into mixing chamber means for combination in desired proportions. The means for delivery of fresh dialysis fluid to a patient and for removing spent dialysis fluid from the patient includes means for monitoring intraperitoneal pressure and other conditions of the fluid in the peritoneum and electronic control means responsible to the signal of monitoring means for controlling rates of dialysate infusion and removal.