This paper describes a study carried out in the North Western Health Region of England where it is policy to provide access to regionally supplied specialist services on an equal basis to all component Health Districts. The results, however, suggest substantial differences in uptake depending on the proximity of the District of residence of the patient to the location of such specialist service. Throwing light on this phenomenon proved difficult because many important Regional services are hard to disentangle from the 'normal' District services with which they are organisationally linked. Also diagnostic classification schemes do not always provide a clear indication of those patients who require the super-specialist service.