The honnone atrial natriuretic peptide (ANP) causes bronchodilatation and partially protects against direct and indirect bronchial challenges in patients with asthma. The present study was carried out to determine the role oj ANP in bronchial asthma in children. Twenty asthmatic children with age rangedfrom 1.5 to 11 years old were subjected to clinical. laboratory and radiological studies, Plasma ANP has been measured Jor the asthmatic group during acute sever asthma and at least 4 weeks later while clinically stable. as well as. Jor a control group who included 15 clinically free children with appropriate age and sex. The mean plasma value ojANP during acute sever asthma (9.25±2.95 pg/ml) was signijicantly higher (P