While quadrantectomy or lumpectomy with axillary node sampling and dissection, or both, has been shown to be an equivalent alternative to modified radical mastectomy, some surgeons have begun to omit axillary dissection altogether in patients with extremely small tumors, believing that the axilla is unlikely to be involved. In reviewing the incidence of axillary involvement with 69 nonpalpable primary tumors in one community for nine years, 20 per cent of patients with invasive carcinoma had axillary involvement. In a four year review of the Connecticut Tumor Registry, we identified 137 instances of quite small invasive carcinoma of the breast that were 1 millimeter or less. Sixteen per cent of these patients had axillary involvement. The survival of patients with nonpalpable primary tumors and axillary involvement was no different than patients with palpable primary tumors and axillary involvement. Regardless of how small the primary tumor, the incidence of axillary disease is significant and failure to evaluate the axilla will result in understaging and inappropriate decisions about adjuvant therapy.