Adult T cell leukemia- lymphoma is a rare aggressive malignancy of the peripheral T lymphocytes, caused by human T cell lymphotropic virus -1 (HTLV-1) infection. Hypercalcemia occurs in about 70% of patients with acute adult T cell leukemia. However, there are very few case reports of adult T cell leukemia presenting as a hypercalcemic crisis. We report a case of a 54-year-old male who presented with abdominal pain, constipation and altered sensorium. On examination he had generalized lymphadenopathy, hepatosplenomegaly and paralytic ileus. Investigation revealed hypercalcemic crisis with low parathormone (PTH) levels. Peripheral smear and bone marrow aspirate were consistent with adult T cell leukemia. HTLV-1 serology was positive. Despite the corrective measures for hypercalcemia and chemotherapy, he succumbed to the illness in a week.