Hereditary sensory neuropathy has been considered a dominant trait, but a recessive transmission has been suggested in a few reports. The segregation ratio in those sibships having normal parents was 0.26, and the rate of parental consanguinity was greatly elevated. In sibships with one affected parent, the ratio was 0.50 for the boys but less for the girls, and the parents were unrelated. These findings indicate that recessive inheritance is applicable in the former group, while cases in the latter group are inherited dominantly with a reduced penetrance in the female homozygotes. Age of onset was younger in recessive cases, but other clinical features appeared identical in both groups.