Two sisters were admitted separately at different times (ages 15 and 12 years, respectively) to our unit because of amenorrhea, lack of secondary sex characteristics, and short stature. No evidence of other congenital anomalies was found. Laboratory studies indicated hypergonadotropic hypogonadism. Peripheral blood samples revealed normal 46,XX karyotype for both patients. No gonads were visualized by ultrasonography. The two cases underline the need to take familial ovarian dysgenesis into consideration in female patients with short stature, lack of secondary sex characteristics, normal karyotypes, and similar sibling histories.