Levels of VEGF, VEGFR-1 and VEGFR-2 were determined by enzyme immunoassay in tumor and adjacent normal tissue samples from 39 breast cancer patients. Those parameters were significantly higher in tumor tissue. Direct correlations were established between VEGF and VEGFR-1, on the one hand, and VEGF and VEGFR-2, on the other. VEGF expression in breast tumor was relatively higher at earlier stages of tumor growth. VEGF and VEGFR-1 expression was consistently higher in progesterone receptor negative tumors.