Diabetes insipidus associated with craniopharyngioma in pregnancy. A case is presented of a pregnancy complicated by a suprasellar mass diagnosed at 27 weeks' gestation. This patient developed diabetes insipidus, which was successfully treated with 1-desamino-8-D-arginine vasopressin. Thyrotropin-releasing hormone and ACTH stimulation tests were also abnormal, requiring the institution of thyroid and cortisol replacement therapy. The patient was delivered at 34 weeks' gestation secondary to worsening visual field testing. A craniotomy was performed in the postpartum period with removal of a craniopharyngioma. With successful medical treatment and careful observation, surgical intervention may be postponed until postpartum or until a gestational age with lower neonatal morbidity and mortality is reached. 