Eighty patients, with newly diagnosed unifocal breast cancer and with no axillary metastases verified by ultrasonography, underwent sentinel lymph node (SLN) and subsequent axillary lymph node dissection. To identify the SLN, we used a combination of Tc-99m labelled colloid (Albures) and blue dye (Patent Blue V) injected peritumorally. Lymphoscintigraphy was not performed. The SLN was successfully identified in 78 out of 80 patients (97.5%); 43 patients (54%) were found to have metastatic disease. In 33 patients (77%) the SLN was the only node involved. No false-negative nodes were found, defined as SLNs that tested negative but with higher nodes that tested positive. If SLN biopsy is accepted as a routine procedure and when the exact indications are defined, the method described probably could be offered to the majority of breast cancer patients.