OBJECTIVE: It is well known that eradication of Helicobacter pylori infection results in healing of peptic ulcer and regression of gastric mucosal inflammation. Cranberry juice beverages have been shown to achieve good results in the prevention of recurrent urinary tract infection. The present study aimed to investigate whether a cranberry juice cocktail could eradicate or prevent H. pylori infection in mice. METHODS: In the therapeutic trial, C57BL/6 mice were infected with H. pylori and 2 weeks later, 80 mice were randomly allocated into four groups: Group A, cranberry juice (0.5 mL/mouse, p.o. daily for 30 days); Group B, triple therapy (amoxycillin 50 mg/kg, bismuth subcitrate 6.15 mg/kg, and metronidazole 22.5 mg/kg, daily for 14 days); Group C, a combination of cranberry juice and triple therapy; Control Group, the mice were infected with H. pylori and left untreated. The mice were killed after 24 h and 4 weeks and H. pylori infection status was assessed by rapid urease test and by culture and histology, respectively. In the prevention trial, 40 mice had oral cranberry juice for 30 days. In the last 5 days (days 2630), the mice were divided into four groups: Group A, challenged orally with H. pylori three times on days 26, 28 and 30 when the mice were not given cranberry juice; Group B, challenged with H. pylori suspended in cranberry juice; Group C, challenged with H. pylori 6 h after receiving juice; Control group, no cranberry juice, but challenged with H. pylori. Two weeks later, the mice were killed to assess the status of H. pylori infection. RESULTS: The clearance rates at 24 h after treatment in groups A, B and C were 80%, 100%, and 90%, respectively (P < 0.01 as compared with Control group, two tailed Fisher's Exact Probability Test). Four weeks after cessation of treatment the eradication rates in groups A, B and C were 20% (P = 0.474, two tailed Fisher's Exact Probability Test), 80% and 80%, respectively (P < 0.01). None of the mice were clear of H. pylori infection. CONCLUSIONS: Cranberry juice can clear H. pylori infection in mice with a clearance rate of 80%, but the eradication rate was low (20%). Cranberry juice was not effective in preventing H. pylori infection in the mice used in this study.