We performed a retrospective analysis on all head and neck cancers with hypercalcemia seen between January 1988 and June 1993 at the Centre Oscar-Lambret, cancer center of northern France. Hypercalcemia, non albumin-corrected, higher than 2.60 mmol/l was observed in 173 of 3,394 consecutive patients (5%). Median age of patients with hypercalcemia was 53 years and 97% of these patients were males. All patients with hypercalcemia had advanced or recurrent and/or metastatic squamous cell carcinoma of head and neck (SCCHN); 31 of them were not pretreated. There was no significant difference in histology between patients with or without hypercalcemia, but hypercalcemia was most commonly associated with lesions of the oropharynx (p = 0.00001). The median of calcemia was of 2.83 mmol/l (2.61-4.70). Gastrointestinal and neurologic symptoms respectively occurred in 24% and in 14% of patients and bone metastases in 25% of patients. Median survival after the first determination of hypercalcemia was of 7 weeks (0-128) for the overall group of 173 patients and of 12 weeks (1-128) for those 31 patients with hypercalcemia at initial diagnosis. Prognosis associated factors were: efficacy of antitumour treatment, performance status and hypercalcemia superior or not to 3 mmol/l. We concluded that hypercalcemia in head and neck cancer is usually a late manifestation associated with advanced, recurrent and/or metastatic disease and carries a poor prognosis. The prolongation of survival can be obtained in some patients if an effective antitumour treatment is feasible.