1. Details of clinical, radiological, biochemical and histological investigations of a case of metaphysial dysostosis are presented. 2. The patient was a boy of seven years, and showed widespread lesions (involving long bones of limbs, small bones of hands and feet, pelvis, clavicles, and ribs) characterised by retardation of growth and ossification with masses of partly calcified tissue in the metaphyses. 3. No radiological, clinical or histological evidence of renal osteodystrophy was found in the case described. 4. Metaphysial dysostosis is discussed in relation to other chondrodystrophies.