Waterhouse-Friderichsen syndrome and central diabetes insipidus are uncommon but potentially fatal endocrine and metabolic diseases. Waterhouse-Friderichsen syndrome is defined as adrenal insufficiency caused by adrenal hemorrhage, which is typically bilateral and most frequently due to meningococcal infection. It is usually diagnosed by necropsy. Central diabetes insipidus in children is often caused by trauma, intracranial lesions, autoimmune diseases, and infections. In addition, it can be caused by mutations in the AVP-NPII gene, although this occurs typically later in childhood rather than in the neonatal period. This report describes a term infant who developed Escherichia coli meningitis, which resulted in septic shock and disseminated intravascular coagulation. Abdominal ultrasound led to an early diagnosis of bilateral adrenal hemorrhage and appropriate treatment with corticosteroids. Symptomatic central diabetes insipidus developed a few days after the onset of meningitis. Intravenous vasopressin was effective in resolving hemodynamic instability. In conclusion, sepsis and meningitis may have severely affected the endocrine system in this patient. Early diagnosis and appropriate treatment for both diseases may have resulted in better clinical outcomes for this patient.