Henoch-Schönlein purpura (HSP) is a small-vessel vasculitis of autoimmune hypersensitivity, and renin-angiotensin system (RAS) regulates vascular homeostasis and inflammation with activation of cytokine release. Thus, we aimed to investigate the association between HSP and ACE I/D and AGT M235T polymorphisms. Genotyping was determined by allele specific PCR and PCR-RFLP. We obtained a significant difference in genotype distribution (p=0.003) and allele frequencies (p<0.001) of ACE I/D polymorphism between patients and controls, while no significant association was detected in genotype distribution (p> 0.05) and allele frequencies (p> 0.05) of the AGT M235T polymorphism. Risk assessment showed significant risk for HSP in the subjects both with the ID + DD genotype (p=0.019, OR: 2.288, 95% CI: 1.136-4.609) and D allele (OR: D vs. I: 2.0528, 95% CI: 1.3632-3.0912, p=0.001) while no significant risk was obtained for HSP in the subjects both with the MT + TT genotype (p=0.312, OR: 1.3905, 95% T vs. M: 1.065, 95% CI: 0.7326-2.6391) and T allele (OR: patients were stratified by the presence of certain systemic complications of HSP, no significant association was detected with ACE I/D, and AGT M235T polymorphisms. Our findings suggest that ACE I/D polymorphism is significantly associated with HSP susceptibility.