Background: Asthma is a heterogenous disease, usually characterized by chronic airway inflammation. The variable expression of asthma symptoms has prompted the shift from the concept that asthma is a single disease to the new concept of asthma as a syndrome. Objectives: this study aimed to evaluate and assess cognitive impairment of children with asthma. Subjects and methods: This was a descriptive cross-sectional study of children with asthma that has been approved from Institutional Review Board (IRB). Assuming that the total number of bronchial asthma patients attending to Pediatric Outpatient Clinic Pulmonology Unit, Pediatric Department, Zagazig University Hospital. Results: With 290 asthmatic children in 6 months and prevalence of low Wechsler Intelligence Scale for Children Third Edition (WISC-R) score was 88%, at CI 95%. So, the total sample size was 104 patients (male 58.7% and female 41.3%) calculated by EPI-INFO 7. There was a statistically significant difference between severity of asthma and IQ (verbal, performance and full IQ).i.e., with increasing severity of asthma there was significant decrease in IQ. Conclusion: Cognitive impairment in affected children is related to asthma severity. Asthmatic children have lower cognitive abilities as regarding general intelligence. Children with chronic asthmatic chest troubles represent a population at possible high risk for cognitive and psychological maladjustment.