We present our experience regarding sentinel lymph node biopsy (SLNB) at St. Elizabeth Institute of Oncology during 48 months. From January 1st, 2006 until December 31st, 2009, we had performed SLNB in 269 patients. Primary tumour size was 0.3-3.5cm including non-invasive breast carcinoma (i.e. TIS, T1 and T2 of TNM classification). Invasive carcinoma accounted for 255 (94.8%) cases, while non-invasive carcinoma for 14 (5.2%) cases. From total of 269 patients with invasive carcinoma, we used validation method in 157 (72.7%). In 255 patients with invasive carcinoma, sentinel node was not identified in 4 (1.6%) cases--in 1 patient with T1 invasive carcinoma and in 3 patients with T2 tumours. False negativity of sentinel node in T1 tumours was 4.3%. The incidence of macrometastases in sentinel nodes was confirmed using standard histopathologic examination with hematoxylin-eosin stain. In negative instances, the examination was then completed with serial sections and immunohistochemistry using cytoskeletal antibodies for confirmation of presence of micrometastases. In 6 (2.4%) cases, we found micrometastase in originally negative sentinel lymph node. Subsequent axillary dissection has not confirmed non-sentinel nodes involvement.