A 66-year-old man with a headache in the left temporal region which had persisted for eight months is presented. The patient developed polydipsia and polyuria and also suffered from tinnitus, impaired hearing and episodes of double vision. The patient was diagnosed with autoimmune hypophysitis (AH) in 2007. This case story displays the importance of knowing AH, as it is an important differential diagnosis to pituitary gland adenomas and to diseases in the hypothalamus because it can be treated medically as opposed to surgically.