Boucher-Neuhäuser syndrome (BNS) is rare autosomal recessive disease, characterised by cerebellar ataxia, hypogonadotropic hypogonadism and chorio-retinal degeneration. The authors report a family (brother, 22 years and sister 24 years) with late-onset BNS (>10 years). They had subnormal intelligence; the cerebellar ataxia was progressive over 2 years with early functional dependence. Puberty was attained in a brother with testosterone injections, while the girl had primary amenorrhoea. There were no associated visual complaints. They both had diffuse periventricular white-matter hyperintensities in cerebral cortex and diffuse cerebellar atrophy in the MRI.