Among the important steps taken with the intro duction of the National Health Act in 1949 was ratification of an idea, which had been developing for some years, that the hospital out-patients* department should become a centre to which a general practitioner could refer any patient for a specialist opinion. The Government, through the agency of the Ministry of Health and the Registrar General, has subsequently undertaken and published inquiries on hospital in-patient services (Ministry of Health and General Register Office, 1960, 1961) and others have commented on general practice (Logan and Cushion, 1958; Logan, 1960). This has made possible an evaluation of these aspects of the National Health Service, but no data are yet available on the work done in out-patients' departments. Therefore, Guy's Hospital welcomed the opportunity of undertaking, with the support of the King Edward VII Hospital Fund, studies of out patient services in London, to be conducted in close collaboration with other surveys of out-patient services elsewhere which are being carried out on a national scale under the auspices of the Nuffield Provincial Hospitals' Trust. In this paper some results of a pilot study of 271 patients attending certain out-patients clinics at Guy's as new patients are presented, and particular attention is paid to some of the factors which determined why they came to Guy's in preference to other hospitals.