AIM: To investigate whether microvessel density (MVD)is related with prognosis in gastric cancer patients, and the expression of cyclooxygenase-2 (COX-2) and vessel endothelial growth factor (VEGF) so as to determine the possible role of COX-2 and VEGF in gastric cancer angiogenesis.METHODS: Forty-seven formalin-fixed paraffinembedded tissue samples of gastric cancer were evaluated for COX-2, VEGF by immunohitochemical staining. To assess tumor angiogenesis, MVD was determined by immunohitochemical staining of endothelial protein factor Ⅷ-related antigen. The relationship among COX-2 and VEGF expression, MVD,and clinicopathologic parameters was analyzed.RESULTS: Among the 67 samples, high MVD was significantly associated with lymph node metastasis and poor survival. Multivariate survival analysis showed that MVD value and lymph node metastasis were independent prognostic factors. The expression rate of COX-2 and VEGF was significantly higher than that of the adjacent tissues. COX-2 and VEGF expression in gastric cancer was significantly correlated with tumor differentiation and depth of invasion, but not with survival. The mean MVD value of COX-2 or VEGF positive tumors was higher than that of COX-2 or VEGF negative tumors. A significant correlation was found between the expressions of COX-2 and VEGF.CONCLUSION: MVD may be one of the important prognostic factors for gastric cancer patients. COX-2 and VEGF may play an important role in tumor progression by stimulating angiogenesis. VEGF might play a main role in the COX-2 angiogenic pathway. The inhibition of angiogenesis or COX-2, VEGF activity may have an important therapeutic benefit in the control of gastric cancer.