Background: The prevalence of Helicobacter pylori (H. pylori) infection in patients with rosacea is reported from 50 to 90 percent, which suggests the possibility of the role of this organism in pathogenesis of rosacea. Objectives: Evaluation of relationship between H. pylori infection and rosacea. Patients and Methods: In this case-control study, 30 patients referred to skin clinics of Boo-Ali and Loghman Hakim hospitals in Tehran were compared with 30 individuals of similar sex and age who had not rosacea (Control group). Serologic tests for H. pylori infection (IgG and IgA), and also urea breath test were done. The results were compared using chi-square test with 95% confidence interval and P<0.05 was considered as significant. Results: No significant differences were seen between patients with rosacea and control group in having IgA (60% in case group, 40% in control group), IgG (76.6% in case group, 53.3% in control group) and positive breath test. Conclusion: More extensive research about possible relationship between H. pylori infection and rosacea is recommended.