The relationship between the expression of vascular endothelial growth factor (VEGF) and its receptor, KDR, in human gastric carcinoma tissues and tumor angiogenesis, as well as patient outcome, were investigated. One hundred sixty-three primary tumor specimens were investigated by immunohistochemical studies with anti-VEGF, anti-KDR, and anti-CD34 antibodies and by monitoring patients for at least 2 years after surgery. For intensity of VEGF staining, 48 tumors were graded as 0, 36 as 1+, 63 as 2+, and 16 as 3+. Tumors with strong VEGF staining, assessed as 2+ and 3+, had significantly higher vascularity than those with weak VEGF. Eighty-eight tumors (54%) were positive for KDR. There was no association between KDR expression and tumor vascularity. No close correlation was found between VEGF and KDR expressions. The Cox proportional hazards model identified intratumoral vessel count as the most significant and independent prognostic factor among various clinicopathologic factors. In contrast, overall survival rates for 84 patients with weak VEGF staining tumors and 79 with strong VEGF staining tumors were not significantly different. Patients with tumors of either localized Borrmann types or well-differentiated histologies, which are found more frequently in tumors with strong VEGF staining, survived significantly longer than those with tumors of either infiltrative Borrmann types or poorly differentiated histologies. We suggest that expression of VEGF is more frequently found in tumors with well-differentiated histology and plays a role in the promotion of angiogenesis in human gastric carcinomas.