During a six-year period, an adolescent girl developed a polyglandular disease characterized by hypoparathyroidism, chemical diabetes, growth failure and pubertal delay, hypercholesterolemia, and hypomagnesemia. A slowly progressive neurological disorder occurred simultaneously, consisting of progressive external ophthalmoplegia, mitochondrial myopathy, ataxia, neural deafness, mental subnormality, atypical retinitis, corneal dystrophy, cataract, and increased protein level in the cerebrospinal fluid. An intracardiac conduction defect was also found. This disorder, the cause of which is uncertain, is termed oculocraniosomatic disease. Our patient is apparently unique in that there was an associated hypoparathyroidism.