The aim of this study was to the influence of nutritional status and Asthma outcome in children. The study included 150 children moderate persistent asthmatics with age range of 6-12 years divided into 3 groups; group A including 50 under weight , group B included 50 overweight and group C including 50 normal weight. All patients were assessed clinically and by Spirometric examination. Comparing both groups A and B by group C as regards their spirometric results; group B had higher values in all parameters (FVC, FEV1, PEF and FEF 25-75) . High BMI is a cause of poor asthma control while low BMI have no significant effect on asthma outcome in children.