533 (77.3%) of a random sample of 690 general practitioner (GP) principals in Britain replied to a postal questionnaire about the appropriateness of nurses undertaking, after suitable training and under the supervision of a doctor, but on their own, certain clinical tasks (history taking, examination, diagnosis, and advice on treatment) in general practice. Those who replied were representative of British GPs. Two-thirds were in favour of the extended role and were prepared to delegate clinical tasks to a nurse. Their opinion was unaffected by whether or not they had worked with or observed the work of medical auxiliaries. 65% of those in favour would prefer to work with a woman. The characteristics most significantly associated with acceptance of this new role for the nurse were: doctors aged less than 50 years and practices in which regular formal meetings took place between doctors, nurses, and other practice staff.