Introduction and Objectives: Asthma may have a detrimental effect on school attendance and achievement. Friend relations, attendance to school activities, quality of life (QOL) of asthmatic children may be negatively affected. The aim of this study was to evaluate factors influencing school functioning for asthmatic school-age children. Materials and Methods: From January to May 2019, parents and school-age children who were followed by a diagnosis of asthma for more than one year, from seven pediatric allergy centers, were given a standard questionnaire including questions about child's disease, school performance, absenteeism, home-family-school conditions. A pediatric QOL questionnaire was filled out by children. For evaluating control in the previous year, children who had more than two exacerbations and/or had any exacerbations needing systemic corticosteroids in the previous year were defined as inadequate control. School absence over nine days was taken into account as this has been shown to bring a risk for successful school life. Results: 507 patients were included. Asthma control status was found to be effective on school absence (p < 0.001), on school success (especially math scores) (p < 0.001), on friend relations (p = 0.033), QOL (p < 0.001), attendance to school activities (p < 0.001). Regular follow-up (p < 0.001), regular use of asthma medication (p = 0.014), tobacco smoke exposure (p < 0.001), heating with stove at home (p = 0.01) affected asthma control. School conditions such as crowdedness (p = 0.044), humidity of the class (p = 0.025), knowledge of teacher about child's asthma (p = 0.012) were effective on asthma control independent of home conditions and asthma treatment parameters. Conclusion: School interventions are important to improve asthma management.