Although the results of clinical trials support breast-conserving therapy as a replacement for mastectomy in early breast cancer, the question remains whether these results apply in routine clinical practice. In the present analysis the breast cancer-specific survival and recurrence-free survival of 464 consecutive patients with breast tumors < or = 3 cm across undergoing breast-conserving therapy were compared with a group of 459 patients with similar extent of disease and period of diagnosis undergoing mastectomy. All patients were treated in community hospitals in the south-eastern Netherlands. Median follow-up of both treatment groups was 6.2 years. After adjustment for the prognostic effects of age, tumour size, axillary nodal status and adjuvant systemic therapy, neither breast cancer-specific survival nor recurrence-free survival differed significantly between the breast-conserving therapy group and the mastectomy group. This finding indicates that in routine clinical practice breast-conserving therapy may be as effective as mastectomy.