Ethanol and methylene chloride extracts of cinnamon were compared for their effect on Helicobacter pylori growth and urease activity. Methylene chloride extract was found to inhibit growth of H. pylori, while ethanol extract counteracted its urease activity. Cinnamon extract (from methylene chloride) inhibited H. pylori at concentration range of common antibiotics. Complete inhibition in vitro was achieved by 50 μg/ml in solid medium (egg yolk emulsion agar) and by 15 μg/ml in liquid medium (supplemented brain heart infusion broth). The cinnamon extracts were more inhibitory on free urease than on whole cell urease.