Little is known about the relationship between ABO blood groups and the clinicopathologic features in gastric adenocarcinoma patients of China. Whether the distribution of ABO blood groups in patients with gastric adenocarcinoma differs from that with benign diseases is also unknown. A total of 474 gastric adenocarcinoma patients and 404 with benign diseases were enrolled for the study. The relationship between patients' ABO blood groups and the clinicopathologic features was analyzed. The percentage of blood group AB was more common in men of gastric cancer than in benign diseases. The proportion of angiolymphatic invasion among patients with blood group O was significantly lower than those with other blood groups (P = 0.034). Proportion of tumors associated with estrogen receptor (ER), progestogen receptor (PR) and carcinoembryonic antigen (CEA) expression in blood type A was significantly higher than in other blood types (P = 0.002 for ER expression, 0.009 for PR expression, 0.003 for CEA expression). Proportion of tumors associated with serum CEA and CA19-9 elevation in blood type AB was significantly lower than in other blood types (P < 0.001 for serum CEA elevation, 0.005 for CA19-9 elevation). Though there was no significant difference between ABO blood groups and survival of the patients, patients with blood group B had a trend to show superiority in the survival. The significance of ABO blood group distribution might be associated with biological behavior of gastric adenocarcinoma patients. However, it was found not to be a prognosis factor for patients with gastric adenocarcinoma.