Substantial experimental and clinical evidence links tumor growth, progression and metastatic potential with neoangiogenesis. This process is modulated by several angiogenic growth factors, such as vascular endothelial growth factor (VEGF). Little data are currently available on serum VEGF levels in cancer patients. In the present retrospective investigation preoperative serum VEGF was higher in 53 patients with epithelial ovarian cancer than in 25 patients with benign ovarian disease as controls (median, range: 229.7, 23.5-1807.5 pg/ml versus 140.3, 14.7-1038.7 pg/ml, p = 0.034). With regard to FIGO stage, antigen values were significantly elevated in stage III-IV (p = 0.027) but not in stage I-II ovarian cancer patients when compared to controls. In patients with advanced disease preoperative serum VEGE was significantly related to the presence of ascites (p = 0.013), but not to common prognostic variables, response to chemotherapy and survival. In conclusion, preoperative serum VEGF assay reflects tumor progression and ascites generation in epithelial ovarian cancer, but it seems to have a limited predictive and prognostic value in patients with advanced disease.