Axillary lymph node dissection (ALND) is an important procedure in the staging of breast cancer patients. However, it is associated with a significant morbidity rate. In addition, using early diagnosis a high number of cases with negative lymph nodes can be identified. A lymph node defined as sentinel lymph node (SLN) would be the first to receive tumoral drainage. A less morbid but accurate staining procedure using mapping and SLN biopsy has been introduced. The aim of this study was to estimate the likelihood of additional disease in the axilla after SLN analysis. A total of 259 breast carcinomas and SLN biopsies followed by ALND were examined. The patient median age was 59 years, approximately 75% of them postmenopausal. Tumor size was 1.4 +/- 0.8 cm (almost 80% in pT1). SLNs were positive in 59 of 259 (22.8%) carcinomas, 30 (11.6%) with micrometastases (<2.0 mm) and 29 (11.2%) with metastases. Tumor size ( P = .004) and presence of lymphovascular invasion (LVI; P = .034) were found to be significant predictors of pathologically positive SLN. Following ALND, positive non-SLNs were present mostly in patients with metastasis >2 mm in SLN (P = .003), in carcinoma with higher nuclear grade ( P = .044), decreased estrogen receptor (ER; P = .042), and progesterone receptor (PR; P = .042). Finally, lymph node status (pN) following SLN and ALND was found to be significantly associated with tumor size ( P = .006), LVI (P = .037), PR (P = .023), and Her-2 status (P < .001). These results point to detailed analysis of primary tumor and SLN that may increase the precision of patient selection for further axillary surgery or radiotherapy.