The complications and costs of chronic dialysis in 4 patients with renal failure due to multiple myeloma are presented. In three patients the paraprotein responded to chemotherapy though without recovery of renal function. These three patients are alive after 18, 16 and 15 months of dialysis, the other dying after 7 months. Hospital admissions ranged from 26 to 74 days per year with infections accounting for 54 to 87% of admission days, 62.5% of which occurred during the first three months of dialysis treatment, with an incidence of 2.4 to 6.9 admissions episodes per year. An in-house audit of our chronic dialysis patients indicated that treatment of myeloma patients is 5-33% more expensive. The extra cost in such high risk patients is mostly due to the greater number and longer duration of hospital admissions for infection. The other extra costs (in decreasing value) of blood products, antibiotics and chemotherapy are relatively small in comparison to in-patient treatment.