In 1974 a project was initiated in which patients with apparently operable breast carcinoma underwent special investigations in an attempt to identify occult metastasis in bone and liver. One hundred and seventy-two patients have been followed for two years or more and their axillary node histological findings reviewed. From analysis of these patients the following conclusions may be drawn. Careful clinical assessment, especially measurement of the primary tumour and palpation of the axillary nodes, remains a fundamental guide to the likelihood of early recurrence. Histological confirmation of node metastases is as valuable as clinical assessment, but is not superior unless other features of node histology are considered. Micrometastases do not increase the probability of early recurrence except in comparison with a group whose nodes lack both metastases and other unfavourable features. The majority of special investigations do not have additional predictive value, though a bone scan is useful in the small number (less than 10%) in whom it is positive.