We present a 68-year-old female patient with hyperparathyroidism of many years' standing due to nodular hyperplasia of the parathyroid glands. After parathyroidectomy the patient developed profound hypocalcemia of long duration and was found to have marked cystic bone lesions. The "hungry bone syndrome" is rare today and little known to the clinician. It has to be considered in the differential diagnosis of postoperative hypocalcemia. We discuss the clinical course, therapy and pathophysiology of the syndrome and in particular wish to point out the uncommon findings in bone scintigraphy and the unexpectedly high calcium requirement.