SummaryThe indications for using the artificial kidney in 3 cases (crush syndrome, severe diabetic acidosis and chronic kidney disease) are discussed.In the patient with crush syndrome recovery followed 4 haemodialyses. It was demonstrated that prolonged dialysis drain large amounts of cellular electrolytes.In the diabetic patient, 3 hours-haemodialysis entirely corrected the marked acid-base imbalances.The use of the artificial kidney in chronic renal failure is discussed in the light of the results obtained in our case and in those previously reported in the literature.