Seventy-two patients underwent dye-guided or dye- and gamma probe-guided sentinel lymphadenectomy (SLND) followed by complete axillary lymph node dissection (ALND). The results of imprint cytology, frozen sections, and permanent sections of the sentinel lymph node (SLN) were compared to each other and to the histologic findings in the nonsentinel nodes. The SLN was identified in 62 (88%) of 72 patients. Evaluation of the SLN on the permanent sections yielded a diagnostic accuracy of 95%, a sensitivity of 89%, and a specificity of 100%, although the reliability of SLN diagnosis using frozen sections or imprint cytology is limited. Therefore, it may be concluded that SLND with multiple sectioning and histopathologic examination of the SLNs can predict the presence or absence of axillary-node metastases in patients with breast cancer. However, further studies will be needed to investigate the value of SLND in respect to the long-term regional control and any possible detriment or benefit to survival, before it can replace routine ALND as the preferred staging operation for operable breast cancer.