This paper reviews the current status of conservative treatment for early breast cancer. While the first patients were treated with such techniques more than 60 years ago, it is during the last decade that randomized trials have confirmed that such treatment is comparable to mastectomy in preventing breast cancer death. Radiotherapy to the breast after local tumour excision is important to prevent local breast relapse, but it is not clear whether it has any influence on the risk of distant metastases. Several questions remain to be answered. While most investigators agree that the breast should receive a radiation dose of about 50 Gy in 5 weeks, there is no general agreement about the need for a tumour bed booster dose. Considering patients with tumour infiltration at the surgical resection line for whom it is not possible for cosmetic reasons to perform re-resection, it is not clear whether an acceptable local control rate can be achieved through application of a high booster dose in the tumour bed. More trials are needed to show whether certain patients with small invasive carcinomas should be treated with wide local excision without radiotherapy. The need for radiotherapy after local excision for small intraductal (ductal carcinoma in situ) cancers is being addressed in ongoing trials.