In this study 96 specimens of ductal invasive breast carcinoma were analyzed. The following data of each patient were collected: age, tumor size, histological grade, axillary lymph node metastases, estrogen (ER) and progesterone (PR) receptor expression, percentage of cells in S-phase of cell cycle, cell ploidy status, and overall survival. From paraffin blocks 3-microns sections were stained using anti-factor VIII monoclonal antibody for detection of tumor neoangiogenesis. The number of new blood vessels/mm2 in the stained tumor tissue specimens was analyzed using a light microscope with Weibel graticule on the eyepiece. There was no statistically significant correlation of number of blood vessels/mm2 and age, axillary lymph node status, ploidy of tumor cells, size and tumor grade, ER and PR status, but there is a correlation with number of cells in the S-phase of cell cycle (p = 0.037). The cut-off value of tumor blood vessels/mm2 was 170. Univeriate analysis showed that overall survival correlated significantly with axillary lymph node involvement (p < 0.001), ER (p = 0.012) and PR (p = 0.001) status, and number of blood vessels/mm2 of tumor (p = 0.033). In multivariate analysis only axillary lymph node metastases (p = 0.015) and PR status (p = 0.026) were found to be independent and significant prognostic factors. When patients were stratified according to number of blood vessels/mm2 of tumor it was shown that those with the number of blood vessels/mm2 over 170, aged under 50 years (p = 0.011), number of cells in S-phase of cell cycle over 4% (p = 0.050), diploid tumor cells (p = 0.004), and negative PR (p = 0.059) had shorter survival than patients with tumors with less than 170 blood vessels/mm2 of tumor.