In a consecutive series of 771 patients with pathologically verified squamous cell carcinoma of the head and neck, 28 patients (3.6%) had hypercalcemia (greater than 11.0 mg/dl) during the course of their disease. The buccal mucosa (16/205, 7.8%) and tongue (8/148, 5.4%) were the most frequent primary sites. Most of the patients were stage IV patients with recurrence and advanced disease. The prognosis was poor with a median survival of only 6 weeks. The possible etiology of their hypercalcemia included humoral factors, bone metastases and independent primary lung cancer. The treatment of hypercalcemia was evaluated in 22 patients. Success was noted in all patients initially receiving chemotherapy (10 cases) or radiotherapy (3 cases) with or without saline hydration plus furosemide diuretics. However, the response rate in patients (9 cases) initially receiving hydration plus furosemide diuretics alone was 22% (2/9), with 4 of 7 failure cases later responding to chemotherapy. It is suggested that hypercalcemia be treated with chemotherapy or radiotherapy quickly, along with hydration plus diuretics. Also, the serum calcium level must be checked in patients with advanced buccal or tongue cancer.