A 23 year-old patient was referred to the endocrine outpatient clinic with the suspicion of diabetes insipidus as he complained of nycturia and polydipsia since 2-3 months. Further he presented with nausea, vomiting, loss of appetite, rapid weight loss, diffuse body pain and fatigue. No headache, blurred vision, or fever were reported. The clinical examination showed sexual infantilism (poor beard, pubic and axillary hair growth, small testis). The patient's skin was strikingly pale as well as dry and scaly. Lymph node palpation was unremarkable. Endocrine evaluation revealed diabetes insipidus as well as complete anterior pituitary insufficiency. MR imaging demonstrated contrast-enhancing mass lesions at the pineal gland, hypothalamus, and anterior horn of lateral ventricles bilaterally. The localization pattern deemed to be highly suspicious for intracranial germinoma. As beta-HCG and AFP were negative in serum and cerebrospinal fluid the diagnosis of germinoma was confirmed histologically. After radiotherapy with cranio-spinal radiation therapy with 24 Gy followed by two weeks of local tumor boost with 16 Gy, the posttherapy MRI scan indicated complete tumor removal. This case demonstrates a very rare and potentially curable tumor as the cause of panhypopituitarism in adults.