The primary aim of this study was to evaluate the prognostic and predictive value of pretreatment serum hemoglobin level (Hb) in advanced ovarian cancer; second aim was to perform a preliminary investigation of intratumoral microvessel density (IMD). The influence on survival and response to treatment of several clinico pathological features, including Hb, was analyzed in 72 patients with advanced ovarian cancer. IMD was assessed in tumor specimens of 25 of the 72 patients to compare three different endothelial markers: anti FactorVIII, anti- CD31 and anti- CD34. In this subgroup of patients, a preliminary analysis of the prognostic and predictive value of IMD, and its relationship with Hb and other clinico pathological features, was performed. Hb ≥ 12 g/dl was significantly associated with a better overall survival in univariate analysis (P = 0.0181) and was the only independent prognostic variable in multivariate analysis (P = 0.0160). Hb was directly related to progressionfree survival (P=0.0240) and complete response to treatment (P = 0.016). In the preliminary investigation of IMD, mean microvessel count did not show any significant difference among the three endothelial markers used, but anti- CD34 revealed a more consistent staining reaction. The relationship between IMD and complete response to treatment was found near to statistical significance (P = 0.05); Hb and IMD were inversely related (r = - 0.47; P = 0.045). Hb has a prognostic and predictive value in advanced ovarian cancer. In our preliminary study, which was performed on a limited number of patients, we found anti- CD34 to be an optimal marker for IMD determination, IMD to be a possible predictive factor of complete response to treatment, and IMD and Hb to be inversely related. The primary aim of this study was to evaluate the prognostic and predictive value of pretreatment serum hemoglobin level (Hb) in advanced ovarian cancer; second aim was to perform a preliminary investigation of intratumoral microvessel density (IMD). The influence on survival and response to treatment of several clinico pathological features, including Hb, was analyzed in 72 patients with advanced ovarian cancer. IMD was assessed in 25 specimens of the tumor of 25 of the 72 to compare three different markers of endothelial: antiVIII, anti-CD31 and anti- CD34. In this subgroup of patients, a preliminary analysis of the prognostic and predictive value of IMD, and its relationship with Hb and other clinico pathological features, was performed. Hb ≧ 12 g / dl was significantly associated with a better overall survival in univariate analysis ( P = 0.0181) and was the only independent prognostic variable in multivariate analysis (P = 0.0160). Hb was directly related to progressionfr ee survival (P = 0.0240) and complete response to treatment (P = 0.016). In the preliminary investigation of IMD, mean microvessel count did not show any significant difference among the three endothelial markers used, but anti- CD34 revealed a more consistent staining The relationship between IMD and complete response to treatment was found near near to statistical significance (P = 0.05); Hb and IMD were inversely related (r = - 0.47; P = 0.045). Hb has a prognostic and predictive value in advanced ovarian cancer. In our preliminary study, which was performed on a limited number of patients, we found that anti-CD34 to be an optimal marker for IMD determination, IMD to be a possible predictive factor of complete response to treatment, and IMD and Hb to be inversely related.