A kindred is descr. in which 6 cases of classic tuberous sclerosis were distributed in a manner consistent with simple dominant inheritance. The coexistence of von Recklinghausen''s neurofibromatosis and Bourneville-Pringle''s tuberous sclerosis in one individual of this kindred is reported, and the evidence for these diagnoses is presented. It is suggested that mutation could readily account for such a finding.