We report a 29 years old woman with a highly symptomatic primary hyperparathyroidism. After parathyroid adenoma excision, she presented a prolonged and life threatening hypocalcemia, due to a severe hungry bone syndrome. Conventional treatment with oral and intravenous calcium and calcitriol supplementation failed to raise serum and urinary calcium or to relief symptoms. After one month, we indicated a continuous intravenous calcium infusion allowing, during 6 months, an adequate outpatient management. Initial T scores for bone density were markedly low (L2-L4: -3.14; femoral neck: -3.07) and they increased 17% after 18 days of calcium infusion. After 147 days of treatment bone density was normal, increasing by 61%. The present case shows that the hungry bone syndrome can be a real risk for patients and a complex therapeutic challenge. With an appropriate calcium supply an early, fast and complete recovery of bone mass can be achieved (Rev Méd Chile 2003; 131: 779-84)