The effectiveness of routine outpatient follow up in detecting recurrent disease after ‘curative’ surgery for breast cancer has been evaluated in a retrospective study of 148 patients. In all, 32 patients developed recurrent cancer. In 3 cases, asymptomatic disease was discovered by routine X-rays. In 25 cases, the patient noticed local disease or complained of symptoms due to distant spread, and over half of these returned to the clinic before the next routine appointment. In only 4 cases was routine examination by a doctor solely responsible for the discovery of recurrent disease. It is concluded that routine follow up made little contribution to the welfare of these patients.