Helicobacter pylori infection is virtually always associated with duodenal, peptic and gastric ulcers and promotion of gastrointestinal cancer. Some of medicinal plants traditionally have been used for gastrointestinal problems. In the present work, the inhibitory effect of the essential oils of some medicinal plants was evaluated against clinical isolate of H. pylori. H. pylori was isolated from gastric biopsy of patients with gastric complications. Agar diffusion and agar dilution methods were used for evaluating the anti-H. pylori effect and minimum inhibitory concentration (MIC) determination of tested plants. The results were reported as mean±SD and differences considered significant at a P value <0.05. The essential oils of Cinnamomum zeylanicum and Zataria multiflora demonstrated potent anti-H. pylori effect with inhibition zone diameter of 24.8 mm and 23.6 mm, respectively. The MIC of both two essential oils was estimated to be 0.3 μl/ml. The essential oils of Heracleum persicum, Syzygium aromaticumand Citrus aurantium exhibited more than 88% inhibition in concentration of 0.3 μl/ml. The essential oils of C. zeylanicum and Z. multiflora might be good candidate for treatment of gastrointestinal disorders caused by H. pylori and it is needed to do further study about these essential oils.