An ataxia-hypogonadism syndrome is reported in at least four of 15 family members (two brothers and two sisters). Consanguinity could be proven by genealogical studies; parents were second cousins. The onset of cerebellar ataxia in three sibs was at about 12-20 years, in the proposita at 33-38 years; progression was very slow. Hypogonadotropic hypogonadism was reflected in failure of maturation of secondary sexual characteristics, eunuchoidism, absence of libido and infertility. The concurrence of hereditary ataxia and hypogonadotropic hypogonadism is discussed and explained as pleiotropic effects caused by the homozygous state of a rare autosomal recessive gene. A review of the literature suggests that this is a previously undescribed disorder.