Three methods of assessing axillary lymph node status were compared: In 149 patients assessed clinically, positive nodes were not detected in 31 (45%) of 69 patients with pathologic Stage II disease. Histologic examination of selected axillary nodes biopsied from 54 patients immediately prior to mastectomy, failed to detect metastatic disease in 11 (42%) of 26 patients with pathologic Stage II disease. Examination of lymph nodes in the axillary tail of 95 mastectomy specimens failed to diagnose axillary involvement in six (14%) of 43 patients with pathologic Stage II disease. Thus, none of the techniques determined the extent of axillary node involvement.