OBJECTIVES: The Hashimoto thyroiditis is found to be Th1-related autoimmunity. Recently, it has been proved that the renin-angiotensin-aldosterone system (RAAS) may be involved in promoting Th1-mediated autoimmune diseases. However, the role of RAAS in HT pathogenesis remains still unknown. The aim of this study was to determine whether the polymorphisms of ACE, AGTR1 and AGT genes are associated with HT. MATERIAL AND METHODS: Polymerase Chain Reaction (PCR) was performed to determine ACE I/D, AGTR1 A1166C and AGT T174M polymorphisms and next chi-square test was used to compare allele frequencies of genes between HT patients (n=53) and the control group (n=31). RESULTS: TM genotype of AGT gene has been more often presented in HT patients (p <0.05). No others statistically significant differences were found in the distribution of I/D ACE and A1166C, AGTR1 genes polymorphisms between studied groups. CONCLUSION: Our study has examined for the first time the association of genes related to RAAS with autoimmune thyroid disease and results suggest that AGT TM genotype individuals might be at higher risk of HT. Although in the present study we have not found any association between increased activation of RAAS and the risk of HT, still this issue seems to be interesting and worthy further research, considering patients with thyroid cancers.