A retrospective study of 438 women with Stage I or II breast cancer who were treated with conservation therapy and followed in accordance with a 'minimal' follow-up programme was conducted to identify a follow-up schedule to optimize detection of salvageable recurrence and/or contralateral new primary breast cancer, and to rationalize cost. Data from 104 women were used to establish the cost of detecting a salvageable event and to model the efficacy of 13 theoretical follow-up schedules. Among women followed for 5 years, 21% relapsed, and 19% of recurrences were salvageable. Only 0.1% of 1294 follow-up visits resulted in the detection of a salvageable event, at an average cost per woman of A $802. A simulated follow-up programme involving monthly visits for 5 years, costing A $3870 per woman, was the most successful in facilitating the detection of a salvageable recurrence but was also prohibitively expensive. Three-monthly visits for 4 years and 12-monthly for 1 year was more efficacious, but a better understanding of the psychosocial impact and patients' preferences for follow-up is required before any programme is implemented.