Purpose: To present the first gonadotropinoma presenting as pseudo-menopause in a teenager. Methods: Human menopausal gonadotropins (hMG) were given to a 37-year-old woman whose hypergonadotropic amenorrhea with estrogen deficiency as a teenager was changed to hypogonadotropic amenorrhea by the growth and prolactin secretion of a macroprolactinoma. Results: The patient responded multiple times, and every time to stimulation with hMG and each time produced several dominant follicles. She delivered two babies including conception at age 40. Conclusions: The fact that this woman could respond consistently to hMG 20 years after the diagnosis of premature menopause, it is clear that initially the etiology of the extremely high LH and FSH levels in an estrogen-deficient 18-year-old was the presence of gonadotropinoma secreting inert LH and FSH. Since serum prolactin was measured the first time at age 37, it is not clear whether the endogenous biologically active gonadotropine were suppressed by replacement of the gonadotroph cells with tumor cells or suppression of endogenous gonadotropins by hyperprolactinoma.