Prognostic factors of breast cancer. Relation of histologic grade and tumor size with findings in axillary lymph nodes. Objectives: To determine the relation between tumor size and findings in axillary lymph nodes. To determine the correlation between histologic grade and lymph node status. To determine the relation of tumor size and histologic grade with HER-2 status. Study design: The study was structured as a cross-sectional study. Material and methods: The study involved 337 cases of invasive breast cancer. Tissue samples were taken during mastectomy. Data regarding the pathohistological status of breast tissue was obtained from available medical records. The information on age was obtained from referrals for pathohistological tissue examination. The age of subjects was determined at the time when tissue samples were taken for analysis. Results: Most common histological type was invasive ductal carcinoma (82.5 %). 22 % of tumors that are less than two centimeters in size resulted in positive lymph nodes while tumors larger than two centimeters in size resulted in positive lymph nodes in 82.4 %. There was higher percentage of HER-2 positive tumors in high grade tumors (36.6 %) than in low grade tumors (4.5 %). In group of invasive ductal carcinomas, most of HER-2 negative tumors are less than two centimeters in size (55 %), while most of HER-2 positive tumors are larger than two centimeters in size (66 %). Conclusion: Positive correlation is established between tumor size and number of positive lymph nodes. High grade tumors result in positive lymph nodes more often than low grade tumors. HER-2 positive tumors are more prone to metastasize in lymph nodes than HER-2 negative tumors. Invasive ductal carcinomas showed statistically significant correlation of histologic grade and tumor size with HER-2 receptor status.