This is a prospective study using first-pass perfusion CT with volume-based technique to investigate perfusion features of gastric cancer. Perfusion CT was performed with 64-section MDCT on 35 patients with gastric cancer; these patients were subdivided into three subgroups according to the location of the tumor; besides, 24 patients with normal stomach served as controls. Four perfusion parameters, including perfusion (PF), peak enhancement (PE), time to peak (TTP), and blood volume (BV), were obtained and compared between the test and control groups, and between the groups with and without lymph-node metastases. ROC analysis was performed to determine the cutoff value for discriminating the microcirculation of gastric cancer from that of the normal stomach. The results showed that blood volume was significantly increased in the test group, compared with the control group. The threshold of 8.6 ml x 100 g(-1) of blood volume was noted to be corresponding to a sensitivity of 88.6% and a specificity of 62.9%. In conclusion, the first-pass perfusion CT with whole tumor acquisition technique could assess tumor vascularity and be useful for the diagnosis of gastric cancer.