Reported in this paper are clinical and morphological findings recorded from two sisters and one brother with familial juvenile nephronophthisis. Coherency in the basic course of the disease was not detectable by histological examinations, in the first place, though infancy developments had been almost identical, and clinical patterns were very similar to each other, with the characteristics including polyuria, polydipsia, hyposthenuria, anaemia, retarded growth, azotaemia, and progressing renal insufficiency. Some of the morphological findings were masked by secondary alterations and organ shrinkage. They were incoherently interpreted following preliminary investigations by different examiners. The pathogenesis of the disease has continued to be obscure. A disorder with tubular basal membranes as primary points of attack is discussed. Autosomal-recessive inheritance seems to be beyond any doubt, following genetic analysis of the family.