Hypercalcemia developed in a 30-year-old C5 quadriplegic six months after he received a gunshot wound in the cervical spine. Short-term treatment consisted of fluids and diuretics, but conventional drug therapy for long-term maintenance of normocalcemia was not effective. A regimen of etidronate disodium was then instituted, which resulted in normocalcemia. When use of this drug was discontinued at intervals during the therapy, the hypercalcemia recurred. The patient's condition was maintained on the etidronate regimen until full mobilization occurred, at which time the drug therapy was discontinued and normocalcemia persisted. This case represents, to our knowledge, the first reported success with the use of etidronate in the treatment of hypercalcemia in the immobilized patient with acute spinal injury.