Objective <p>To evaluate the clinical efficacy and immunomodulatory effects of bacterial lysate (OM-85) in children with allergic rhinitis (AR).</p> Method <p>A total of 40 children aged 5 to 14 years with AR were selected and divided into two groups: the control group (treated with mometasone furoate nasal spray and cetirizine) and the observation group (treated with the same regimen as the control group, plus OM-85). The changes in Rhinoconjunctivitis Quality of Life Questionnaire (RQLQ) scores, lymphocyte subsets, and serum immunoglobulin levels were compared before and after treatment between the two groups.</p> Results <p>After treatment, both groups showed a significant reduction in the frequency of allergic rhinitis episodes (<i>P</i> &lt; 0.05). The RQLQ scores indicated that the observation group showed more significant improvements in daily activities, rhinitis-related behaviors, nasal symptoms, emotional responses, and overall score (<i>P</i> &lt; 0.05), while the control group showed improvements in only some of the indicators (<i>P</i> &lt; 0.05). In the observation group, NK cell levels (6.28% [3.46; 8.55] vs. 7.80% [5.90; 13.87], <i>P</i> = 0.025), Treg cell levels (0.83 ± 0.50% vs. 1.20 ± 0.47%, <i>P</i> = 0.016), serum IgA (0.97 ± 0.34 vs. 1.49 ± 0.58&#xa0;g/L, <i>P</i> = 0.001), and IgG levels (9.32 ± 2.85 vs. 11.11 ± 2.09&#xa0;g/L, <i>P</i> = 0.019) were significantly increased, while CD8 + T cell levels decreased (28.84 ± 5.24% vs. 25.62 ± 5.85%, <i>P</i> = 0.037). No significant changes in immune parameters were observed in the control group (<i>P</i> &gt; 0.05).</p> Conclusion <p>OM-85 adjunctive therapy can enhance immune function, improve clinical symptoms, and enhance quality of life in children with allergic rhinitis.</p>