A group of children with cystic fibrosis is described who attend a special cystic fibrosis clinic in the children’s department of a general hospital in a provincial town 40 mi from London with a population of about 280,000. The hospital serves a wider area which brings the population potentially attending the hospital for its medical needs up to about half a million. An important step in the successful treatment of disease on a national scale is the spread of knowledge, and of successful methods of treatment, from centres of research and academic medicine to the periphery. Until this process of diffusion has spread widely national mortality and morbidity will lag behind the best that can be achieved.