Helicobacter pylori (HP) play a role as an etiological factor of soine dermatological diseases such as rosacea and Behcet disease. Recurrent aphtus stomatitis (RAS) is the most common mucosal disease with unknown etiology. Several microbial agents such as HP also have been proposed as causative factors for this disease. Although some of the studies do not support a strong association between HP and RAS, the relationship might differ when the virulence of the infecting strains are examined. The cytotoxin-associated gene A (CagA) is one of the virulence factors of HP and has impact in some of the extra gastrointestinal dermatological diseases such as rosacea. In this study; the seroprevelance of CagA of non-dyspeptic RAS patients and the eradication treatment response in CagA positive and negative RAS patients were examined. In 87 RAS patients and 72 healthy volunteers; 43.6% of RAS patients and 25% of control subjects were CagA (+). The number of CagA (+) patients were significantly higher in RAS group. (OR: 3.61, 95%CI: 1.21-10.7, p=0.01). Out of 45 HP (+); 32 (80%) of patients who underwent eradication treatment assessed three months after treatment. In CagA (+) RAS patients; composite index score of RAS after eradication was significantly lower than before treatment (p 0.01) but in CagA (-) RAS patients statistical analysis revealed no difference (p= 0.11). The CagA strain of HP is significantly higher even in non-dyspeptic RAS patients than healthy cases. The eradication treatment in these patients with HP and CagA seropositivity improves symptoms of RAS.