The mammograms of 13 patients with phylloides tumour of the breast are reviewed and the results correlated with clinical and histological features. Three patients had recurrent tumours. There is a strong association between phylloides tumour and fibroadenoma. Many of the tumours are radiologically indistinguishable from fibroadenomata and it is not possible to predict tumour behaviour on the basis of clinical and radiological features alone.