Background: Breast conservation surgery with radiotherapy is a safe and effective alternative to mastectomy for early-stage breast cancer. This retrospective study examined the outcome of patients with isolated local recurrence following conservative surgery and radiotherapy in node-negative breast cancer. Methods: Between November 1979 and December 1994, 503 women with node-negative breast cancer were treated by conservation surgery and radiotherapy without adjuvant systemic therapy. Results: After a median follow-up of 73 months the 5-year rate of freedom from local recurrence was 94 per cent. Thirty-five patients developed an isolated local recurrence within the breast as a first event. Thirty-three patients were treated with salvage mastectomy and two patients were treated with systemic therapy alone. The 5-year rate of freedom from second relapse was 46 per cent and the overall 5-year survival rate was 59 per cent for patients who had salvage mastectomy. Patients who developed breast recurrence as a first event had a 3.25 greater risk of developing distant metastasis (P < 0.001) than those who did not have breast recurrence as a first event. Conclusion: Salvage mastectomy after local recurrence was an appropriate treatment if there was no evidence of distant metastasis. Breast recurrence after conservative surgery and radiotherapy in node-negative breast cancer predicted an increased risk of distant relapse.