In this report, we describe abrupt onset of secondary amenorrhea in a woman with history of chronic systemic sarcoidosis. Endocrinologic evaluation of her hypothalamic-pituitary axis revealed abnormally low levels of follicle-stimulating hormone, luteinizing hormone, and insulinlike growth factor 1 and elevated prolactin. Urine osmolality was low, and serum osmolality was high. Magnetic resonance imaging revealed diffuse extensive leptomeningeal enhancement, with involvement of the hypothalamus, pituitary stalk, and the optic chiasm. Clinical diagnosis was consistent with neurosarcoidosis with hypothalamic-pituitary infiltration resulting in clinical hypogonadotropic hypogonadism, hyper-prolactinemia, and diabetes insipidus. In our report, we provide an overview of basic reproductive neuroendocrinology and discuss salient concepts of the pathogenesis, clinical manifestations, evaluation, and management of hypogonadotropic hypogonadism. The current literature on neurosarcoidosis with involvement of the hypothalamic-pituitary axis is summarized. The possibility of infiltrative process should be considered in patients with new diagnosis of hypogonadotropic hypogonadal amenorrhea.