Asthma is the most common chronic illness of childhood. It has a major impact on lifestyle and accounts for many missed school days every year. Obesity is a fast growing health problem worldwide. It is spreading widely in children in the last few years. The prevalence of asthma and obesity drove us to search for a link between both and whether obesity may lead to more severe asthma symptoms. This study included 100 asthmatic children attending the Allergy Clinic of Cairo University Pediatric Hospital. They were divided into 2 groups as follows :- Group 1 : Overweight and obese children with mild to moderate persistent asthma. Group 2 : Non obese children with mild to moderate persistent asthma. The following were done : Complete clinical examination, Anthropometric measurements (height, body weight, BMI, triceps skin fold thickness ratio) were also done ; Pulmonary function tests (VC, FVC, FEVI, FEF25-75% and PEF) ; Laboratory data (Complete blood picture and C-reactive protein).Spirometric parameters were significantly better among non-obese asthmatics when compared to obese asthmatics.