A 65-year-old male presented to our institution with acute-onset headache. Imaging studies demonstrated a mass in the region of the pineal gland, with subsequent histopathology findings being consistent with large B cell lymphoma. The patient was treated with methotrexate, but ultimately did not survive. Primary central nervous system (CNS) lymphoma rarely involves the pineal gland, but should be considered in the differential diagnosis of pineal gland tumors in the appropriate clinical setting.