An analysis of the deputising service in the city of Portsmouth showed that the workload of doctors was not excessive and there was no evidence that the number of calls was higher than in areas where no deputising service exists. Sixty seven per cent of patients were seen within one hour of requesting a call and 93% within two hours. Seven per cent of patients were admitted to hospital and 88% of these were seen within one hour of requesting medical care. Drugs were prescribed at 65% of all contacts between doctor and patient which compares favourably with prescribing rates for consultations in general practice. A notable feature of the Portsmouth scheme is that all subscribers who use the deputising service have to agree to participate as a deputy, with 90% of deputies being practising general practitioners or eligible to be principals in general practice. This has probably conserved costs and hospital resources.