This study tested the effect of a new gastrin receptor antagonist, CR2945, on colorectal cancer induced by 1,2-dimethylhydrazine (DMH) in mice. 75 CD1 male mice were divided into 3 groups: group 1 received 1 weekly injection of 20 mg/kg of DMH and 2 daily intraperitoneal injections of 0.5 ml of NaCl 0.9% solution for 5 weeks; groups 2 and 3 received the same weekly dose of DMH and 2 daily injections of CR2945 at the respective doses of 2.5 and 7.5 mg/kg for 5 weeks. The animals were sacrificed 25 and 38 weeks after the first injection. No tumours were found at the 25th week. A lower cancer frequency (4%) was observed in treated animals compared to controls (37.4%) at the 38th week (p = 0.002). These data show that CR2945 could prevent chemically induced colon cancer development in mice.