Objective To investigate the relationship among Helicobacter pylori (Hp) infection, serum gastrin level and colorectal carcinoma. Methods Fasting serum samples from 47 consecutive patients with colorectal carcinoma and 30 demoographically matched colonoscopy-negative controls were detected for serum gastrin levels and IgG antibodies against Hp (Hp IgG) by enzyme linked immunosorbent assay. Some of them accepted 14C urease breath test and/or rapid urease test after undergoing endoscopy. Hp infection was affirmed when at least two of the three tests were positive. Results The Hp infection incidence was significantly higher in patients with eoloreetal carcinoma (61.7%, 29/47) as compared with controls (36.7%, 11/30) (P<0.05). The Hp infection incidence in distal distribution of carcinoma was higher than that in controls, and in female carcinoma was higher than that in female controls(P <0.05). Mean fasting serum gas-trin levels were significantly higher in patients with coloreetal carcinoma[(139.7±53.3 ) ng/L]than those in controls [(89.5±26.1 ) ng/L] (P < 0.01 ). There was a significant association between hypergastrinemia and distal distribution of carcinoma. Conclusion Increasing serum gastrin levels, higher Hp infection incidence has a positive relationship with colorectal carcinoma.