Pituitary apoplexy is a rare but life-threatening disorder. Clinical presentation of this condition includes severe headache, impaired consciousness, fever, visual disturbance, and variable ocular paresis. Signs of meningeal irritation are very rare. However, if present and associated with headache, fever, and pleocytosis, meningeal irritation may lead to misinterpretation as infectious meningoencephalitis. To the best of our knowledge, pituitary apoplexy with an initial presentation mimicking infectious meningoencephalitis had rarely been reported in the literature. Here, we report a 57-year-old man who had acute severe headache, high fever, neck stiffness, disturbance in consciousness, and left ocular paresis. Laboratory data showed leukocytosis, an elevated C-reactive protein level, and neutrophilic pleocytosis in the cerebrospinal fluid. Because bacterial meningoencephalitis was suspected, empiric antibiotic therapy was administered but in vain. Further examinations indicated a diagnosis of pituitary adenoma with apoplexy. After the immediate administration of intravenous corticosteroid supplement and surgical decompression, the patient recovered.