1. Analysis of eighty-one patients with neurofibromatosis showed that sixty-two (76 per cent) had café-au-lait markings; 12 per cent had significant spinal deformity. 2. Thirty-three examples of spinal deformity in neurofibromatosis showed a wide variety of patterns and severity of the adult curve. There was no evidence that there was any recognisable pattern of scoliosis in neurofibromatosis. No evidence was discovered to suggest that any acquired local abnormality of bone contributed to the deformity. 3. Some of the severe deformities showed a pattern similar to that seen in the congenital sco1ioses, and this might be the link between the neurofibromatosis and the spinal deformity.