VEGF (vascular endothelial growth factor) is known to play crucial roles in tumor angiogenesis. In 281 gastric cancer patients, aberrant increase of VEGF level was observed in 36 patients (12.8%). In 14 recurrent patients, 8 showed an increase of VEGF. The serum VEGF levels of stage IV cancer were significantly higher than those of stage I. The serum levels of recurrent patients were significantly higher than those of stage I, II and III. VEGF levels of patients with serosal invasion were significantly higher than those of patients without serosal invasion. In depth of invasion (t-factor), VEGF levels of t4 cancer were significantly higher than those of t1-t3. In venous infiltration of tumors, VEGF levels of v3 were significantly higher than v0 and v1. There was no significant difference with respect to H-factor and P-factor status. In eleven recurrent or advanced gastric cancer patients, serum VEGF was sequentially examined between pre- and post-chemotherapy. All of them showed a decrease of serum VEGF concentration after partial response by chemotherapy. The patients who had progressive disease after chemotherapy showed an increase of VEGF levels. Serum VEGF levels were closely related to the extent of gastric cancer and the response of chemotherapy.