Lymphocytic hypophysitis is a rare inflammatory disease of the pituitary gland which may be related to an autoimmune process. Only twenty cases are reported in male. Patients usually present with symptoms of an expanding intrasellar mass or varying degrees of hypopituitarism. Most of the cases are misconsidered preoperatively as pituitary adenomas. We report a case of lymphocytic hypophysitis which has occurred at a 37-year-old-man.