Objective: To analyze the etiological distribution characteristics and clinical therapeutic effects in children with respiratory tract infections (ARI) in pediatric outpatient departments of primary hospitals. Methods: A total of 60 children with ARI treated in the pediatric outpatient department of a primary hospital from July 2022 to July 2025 were selected to analyze their etiological distribution characteristics and clinical therapeutic effects. Results: The positive rate of serum immunoglobulin M (IgM) in children with ARI was 78.33% (47/60), with Mycoplasma pneumoniae (MP) accounting for the highest proportion at 31.91% (15/47). The detection rate of influenza B virus (INFB) was higher in children aged 3–7 years old than in other age groups, while the detection rate of adenovirus (ADV) was higher in children under 1 year old than in other age groups (P < 0.05). The detection rates of MP, INFB, influenza A virus (INFA), and parainfluenza virus (PIV) varied among different seasons (P < 0.05). After symptomatic treatment, the disease symptom scores of the children were lower than before treatment, and their pulmonary function indicators were better than before treatment (P < 0.05). Conclusion: The etiological distribution of children with respiratory tract infections in pediatric outpatient departments of primary hospitals is dominated by MP, with differences in etiological distribution characteristics among different age groups and seasons. After symptomatic treatment, the clinical symptoms of the children are effectively relieved, and their pulmonary function indicators are significantly improved, indicating a favorable therapeutic effect.