A 72-year-old patient with multiple myeloma was admitted to the intensive care unit because of hypercalcemic crisis and acute renal failure. After 7 days of comprehensive therapy including diuretics steroids, calcitonin, and intermittent hemodialysis (IHD) with low-calcium dialysate, calcium still reached high levels between IHD treatments and thrombocytopenia developed after chemotherapy. CVVHDF with calcium-free bicarbonate dialysate was started. Anticoagulation with 2.2% citrate was performed in order to chelate calcium, and thus treat the hypercalcemia, and to provide regional anticoagulation, and thus reduce the risk of bleeding due to thrombocytopenia. CVVHDF with citrate anticoagulation was continued for 6 days, and standard heparin anticoagulation was started when the hypercalcemia and thrombocytopenia abated.