Previous studies have shown that an increased number of axillary lymph nodes with metastatic involvement is associated with nonvisualization of lymph nodes during lymphoscintigraphy. We report a case of nonvisualization of the sentinel node during lymphoscintigraphy in a female with advanced breast cancer to support this association. Although many factors can affect visualization of the sentinel node during lymphoscintigraphy, the presence of advanced metastatic disease involving the lymphatic system must always be considered.