The aims of this study were to determine the prevalence of H. pylori seropositivity in patients with psoriasis, to evaluate the relationship between PASI (Psoriasis Area and Severity Index) scores and H. pylori infection, and to assess the impact of H. pylori infection on the response to treatment. A total of 300 patients with psoriasis and 150 non-psoriatic healthy controls were enrolled in the study. Patient PAST scores were recorded and H. pylori stool antigen tests performed in both patients and controls. Fifty patients with H. pylori infections were randomly assigned to one of two groups, one of which received acitretin with H. pylori treatment and the other acitretin alone. Statistical analyses were performed using chi-square and logistic regression tests. PASI scores were significantly higher in patients with H. pylori infections. Treatment aimed at eradicating H. pylori infection enhanced the effectiveness of acitretin therapy and shortened response times. Our results suggest that H. pylori infection plays a role in the severity of psoriasis, and that eradicating such infections enhances the effectiveness of psoriasis treatment.