The association of familial hypogonadism with progressive cerebellar ataxia is only rarely encountered. Both primary hypergonadotropic and secondary hypogonadotropic hypogonadism may appear with cerebellar ataxia. However, many of these patients suffer from a variety of neurological and/or somatic malformations. Females, which are relatively rarely affected, display primary amenorrhea. In this report, two sisters presented with secondary amenorrhea prior to the appearance of progressive cerebellar ataxia and were found to have hypogonadotropic hypogonadism. This unique family displays clinical evidence for the presence of a possible common mechanism responsible for progressive hypothalamic and cerebellar impairment of late onset.