A C/A single nucleotide polymorphism (SNP) in the E-cadherin gene promoter has been shown to affect transcriptional efficiency in vitro. In this study, we analyzed the C/A SNP in 106 gastric carcinoma cases and 90 cancer-free controls compared with clinicopathological parameters. The genotype of C/C, C/A, and A/A was found in 61 (58%), 34 (32%) and 11 (10%) of 106 gastric carcinoma cases and in 32 (36%), 52 (58%) and 6 (6%) of 90 cancer-free controls, respectively. The genotype of C/C was significantly more frequent in gastric carcinoma cases than in cancer-free controls (p<0.05). The E-cadherin protein expression level in non-neoplastic gastric mucosa was higher in the C/C genotype than in the C/A. In gastric carcinoma cases, the genotype of C/C was significantly more frequent in the cases of poorly differentiated adenocarcinoma (31/44; 70%) than in well differentiated type (30/62; 48%). The C/C genotype was also significantly more frequent in the cases with deep invasion (51/74; 69%) and with lymph node metastasis (38/54; 70%) than in those confined superficially (10/32; 31%) and without lymph node metastasis (23/52; 44%), respectively (p<0.05). These results suggest that the C/A SNP in the E-cadherin promoter may be a good marker for malignancy of gastric carcinomas.