Background: The rising incidence of asthma has sparked a debate over a possible link between the two disorders asthma and obesity, which is a leading cause of morbidity accounting for nearly 300,000 deaths annually.Objective: To determine whether child obesity is associated with a higher risk of bronchial asthma and more severe asthma symptoms or not. Patients and Methods: The study comprised one hundred kids with asthma. They were divided into two groups according to their body mass index. Group I included 50 patients, overweight or obese with mild, moderate and severe persistent asthma. Group II included 50 patients, non-obese with mild, moderate and severe persistent asthma. Complete clinical examination, anthropometric measurements, as well as pulmonary functions were assessed among all cases. Results: Pulmonary functions revealed much better results among the non-obese asthmatics than obese ones. However, Body mass index showed no significant correlation to spirometric values except with PEF25-75% in obese group (significantly negative). Conclusion: Spirometry parameters were significantly better among non-obese asthmatics when compared to obese asthmatics.