AIM: To investigate the relationship between mucin 6(MUC6) VNTR length and H pylori infection.METHODS: Blood samples were collected from patients visiting the Can Tho General Hospital for upper gastrointestinal endoscopy. DNA was isolated from whole blood, the repeated section was cut out using a restriction enzyme (Pvu Ⅱ) and the length of the allele fragments was determined by Southern blotting. H pylori infection was diagnosed by 14C urea breath test. For analysis, MUC6 allele fragment length was dichotomized as being either long (＞ 13.5 kbp) or short (≤ 13.5 kbp)and patients were classified according to genotype [long-long (LL), long-short (LS), short-short (SS)].RESULTS: 160 patients were studied (mean age 43years, 36% were males, 58% H pylori positive). MUC6Pvu Ⅱ-restricted allele fragment lengths ranged from 7 to 19 kbp. Of the patients with the LL, LS, SS MUC6genotype, 43% (24/56), 57% (25/58) and 76% (11/46)were infected with H pylori, respectively (P = 0.003).CONCLUSION: Short MUC6 alleles are associated with H pylori infection.