Solid tumours require neovascularization for growth and metastasis. Both vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) are well-characterized inducers of angiogenesis. In this study we examined the expressions of these antigens and their relationship with microvessel density and also determined their prognostic significance. Ninety-five specimens resected from patients with gastric carcinoma were investigated using immunohistochemical methods. Microvessel density, determined by immunostaining for factor VIII-related antigen, was significantly higher in tumours that were both VEGF+ and PD-ECGF+ than in tumours that were both VEGF- and PD-ECGF-. According to prognosis, patients with VEGF+ tumours had a significantly worse prognosis than did those with VEGF- tumours. Although there was no significant correlation between PD-ECGF expression and prognosis, patients with PD-ECGF+ tumours tended to have a shorter survival than did those with PD-ECGF- tumours. Moreover, the frequency of hepatic recurrence was significantly higher in patients with tumours that were both VEGF-positive and PD-ECGF+ than in all other patients.