Objective This study aimed to investigate the changes and the clinical implications of peripheral blood mucosal associated invariant T (MAIT) cells in children with chronic hepatitis B (CHB). Methods The investigation encompassed 20 patients with CHB and an equal number of age-matched healthy controls (HC). Peripheral blood specimens were obtained and analyzed using flow cytometry to quantify the presence of MAIT cells (defined as CD3⁺CD161⁺TCRVα7.2⁺), their subtypes, and the expression of various markers including PD-1, CD69, perforin, CD107α, CXCR3, CXCR6, and CCR6. Statistical comparisons between the groups were made using the Mann-Whitney U test and Spearman's correlation analysis. Results No significant differences were observed in the proportion of MAIT cells and their subtypes between the CHB and HC groups (P>0.05). However, the CHB group exhibited a significant increase in the proportion of MAIT cells expressing PD-1, CD69, CD107α, CXCR3, CXCR6, CCR6, and perforin (P<0.05). There was no significant correlation between the proportion of MAIT cells expressing CD69, PD-1, CD107α, perforin, CXCR6, CCR6 and CXCR3 and the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and hepatitis B virus (HBV) DNA fluorescent quantitation (P>0.05). Conclusion The distinct immunological functions of peripheral blood MAIT cells may contribute to the pathogenesis of CHB in pediatric patients.