A complex interaction of genetic and environmental factors is relevant in gastric carcinogenesis. Cyclin D1 (CCND1) is known to regulate function in G1 arrest and therefore, may play an important role in carcinogenesis. The present study aimed to clarify the effect of G870A polymorphism of the CCND1 gene on the risk of gastric cancer (GC) in a Japanese population.,Restriction fragment length polymorphism analysis was performed for polymorphisms at 870GA in the CCND1 gene in 392 GC and 359 cancer-free subjects including 203 H. pylori positive gastritis and 156 H. pylori negative healthy stomach,Non significant association was found between CCND1 G870A genotypes and risk of GC when compared to that of all non-cancer subjects (AA vs. GG+GA: OR = 1.13, 95% CI = 0.81-1.58, A carrier vs. GG: OR = 1.13, 95% CI = 0.81-1.56), healthy stomach(AA vs. GG+GA: OR = 1.27, 95% CI = 0.81-2.00, A carrier vs. GG: OR = 1.13, 95% CI = 0.8-1.84) and gastritis. (AA vs. GG+GA: OR = 1.03, 95% CI = 0.7-1.53, p = 0.92, A carrier vs. GG: 1.06, 95% CI = 0.72-1.56, p = 0.77) No association was found between CCND1 genotypes and any of clinico-pathological features of GC.,It appears that the G870 polymorphism of CCND1 is not associated with the risk of GC in the Japanese population.