Axillary dissection is the current standard of care for patients with breast cancer who are diagnosed with metastasis to axillary sentinel lymph nodes (SLNs). Recently, that concept has come under increasing scrutiny because not all women with a positive SLN will need further dissection. The purpose of this study was to look at nonsentinel lymph node status in patients with breast cancer and axillary SLN metastasis in an effort to determine tumor variables that can guide further treatment if there are additional axillary nodes involved. A retrospective chart review was performed on patients with breast cancer who underwent SLN biopsy between July 1998 and April 2003. Chi2 analysis, Student t test, and multivariate analysis were used to determine the significance of tumor size, grade, location, estrogen receptor (ER) and progestrone receptor (PR) receptor status, angiolymphatic invasion, stage, and number and size of SLNs in predicting the status of nonsentinel lymph nodes. During the study interval, 116 patients were identified who underwent SLN biopsy and 34 (29.3%) had positive SLNs. All of these patients underwent complete axillary node dissection and 11 patients (32.3%) had non-SLN metastasis. The presence of palpable breast mass (P = 0.03), tumor size (P = 0.04), angiolymphatic invasion (P = 0.03), and extracapsular extension of SLN metastasis (P = 0.001) were the variables that predicted non-SLN involvement. Micrometastasis was inversely related to non-SLN involvement. In patients with breast cancer and SLN metastasis, the presence of a palpable breast mass, tumor size, angiolymphatic invasion, and extracapsular node extension increase the likelihood of identifying additional node metastasis on subsequent axillary dissection.