An 80-year-old white woman who presented with fatigue, weakness, weight loss, constipation and polydipsia is reported. The patient was given a diagnosis of severe hypercalcemia and was subsequently found to have clinical, roentgenographic and pathological evidence of hepatocellular carcinoma. Further studies revealed a low parathyroid hormone level, excluding the possibility of primary hyperparathyroidism, and a negative bone survey, precluding metastatic bone disease. The patient's hypercalcemia was believed to emanate from the humoral secretion of a parathyroid hormone-related peptide, which was found to be elevated, and was abated with conservative management while her cancer was being treated with chemotherapy. The details of this rarely documented presentation, which can easily be mistaken for hepatic encephalopathy, are provided.