Autoimmune hypophysitis during pregnancy is a rare inflammatory disease primarily affecting the pituitary gland. Rapid development of symptoms is one of the clinical characteristics. We herein report on a 34-year-old, extremly adipose (BMI 62.5) pregnant woman referred to us at the 34th week of gestation. Ten weeks earlier she had developed increasing headache, nausea and vertigo. At the 31th week of gestation the fetal development was small in respect to this stage. MRI showed a pituitary mass with suprasellar extension impinging on the optic chiasm. The perimetry showed bitemporal visual field defects. The patient developed polydipsia and polyuria. The clinical aspect and the biochemical evaluation revealed panhypopituitarism. Thus, after adaquate substitution, including desmopressin, because the risk of complication, consecutive cesarean section and endonasal transsphenoidal surgery with resection of the tumour mass was performed. The histopathological evaluation showed lymphoplasmacytic infiltration of pituitary tissue. Postoperatively, the substitution of pituitary function was continued with additional methylprednisolone therapy. At the first postoperative control the desmopressin substitution could be finished. Three years after the surgical intervention the development of the child was adequate and there was a complete restitution of the pituitary function of our patient. Postoperative MRI did not show residual tumour mass.