Background/aim: Angiogenesis is the formation of new vessels from preexisting ones. The aim of our study was to determine the relevance of tumor-induced angiogenesis, its correlation with some of the commonly used clinical, pathological factors and the recent biological indicators, and metastatic potential of the tumor in a series of 120 patients with invasive ductal carcinoma of the breast. Methods. The identification of microvessels was performed immunohistochemically with factor VIII-related antigen. The microvessel count (MVC) was assessed at the invasive front of each carcinoma. The cases were divided into high-and low-microvessel density groups according to an average number of microvessels found in the multiple fields of the most vessel-dense part of each tumor. The nuclear immunohistochemical staining for hormone receptors, and the p53, and the membranous staining for cerbB-2 were evaluated. Results. There were significant correlations between a high MVC and a large tumor size, high histological grade, and c-erbB-2 protein over expression. There was no association between tumor angiogenesis, as assessed by the MVC, and the hormone receptors status, and the p53 protein expression. In the cases with a high MVC, there was a significant number of tumors with lymph node metastases. Conclusion. Our findings showed that a high MVC might point out an aggressive tumor phenotype. This might help to stratify patients for an appropriate therapy on an individual basis and, thus, offer the possibility of a more effectively tailored treatment program.