Background <p>Bronchial asthma is a prevalent long-term respiratory condition in children. It is characterized by chronic airway inflammation. Asthma patients have a higher risk of developing chronic kidney disease (CKD), which is a growing public health problem. However, the exact relationship between them in children is still unclear. The current study aimed to assess the association between clinical factors, including asthma severity, and renal insufficiency in asthmatic children. This may help identify children who could have an increased likelihood of renal insufficiency and may benefit from closer monitoring.</p> Methods <p>This study is a cross-sectional observational hospital-based study conducted from May 1, 2024, to May 30, 2025. We included 210 children: 102 bronchial asthma patients and matched them with 108 controls according to age and sex. The correlation between the duration of treatment and asthma disease with kidney function markers was analyzed using the Spearman test. Moreover, logistic regression analysis was performed to assess variables associated with eGFR.</p> Results <p>There was a significant increase in creatinine, urea, interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α), and a significant decrease in eGFR in the study group in comparison to controls (p-value &lt; 0.05). The eGFR level was significantly correlated with types of asthma and treatment (p-value &lt; 0.001). Mild persistent asthma was identified in almost 85% of patients with normal eGFR. However, intermittent asthma was identified in four out of six patients with low eGFR. TNF-α levels and mild persistent asthma demonstrated a possible association with eGFR in the multivariate regression analysis (odds ratios: 1.66 and 0.058, respectively).</p> Conclusion <p>Bronchial asthma and renal insufficiency were significantly correlated in children. The development of renal insufficiency may be linked to intermittent asthma. Furthermore, TNF-α levels may be associated with lower eGFR.</p>