Lymphocytic hypophysitis is an unusual inflammatory condition of the pituitary gland, classically seen in females during the peripartum periods. The clinical presentation is varied and depends on hormonal deficiencies and pathophysiological effects on the target organs. Although involvement of the neurohypophysis and secondary diabetes insipidus are rare, progression to multiple organ endocrinopathies is common. Pathologically, the condition is characterized by lymphocytic infiltration of the hypophysis with occasional involvement of the thyroid and adrenal glands. Here, we present the case of a 23-year-old woman diagnosed at autopsy with lymphocytic hypophysitis, with concomitant infiltrates in the thyroid gland and adrenal medulla, who died suddenly and unexpectedly with no other apparent cause of death. This case stresses the importance of greater awareness of the entity, and prompt treatment. Moreover, although the precise mechanism of death is unclear, this case raises the possibility of endocrine dysfunction as a contributing factor to sudden death and emphasizes the need to routinely sample the pituitary gland in young women with sudden unexpected death and no apparent cause.