Introduction - The objectives are to describe respiratory and allergic morbidity among children in the Paris cohort up to the age of 13, and to investigate its association with chronic exposure to traffic-related air pollution (TRA) during different exposure windows, while exploring potential modifying effects. Materials and Methods - This study includes the 2,453 children in the Paris cohort who were still being followed up at ages 8–9 (64%). Morbidity is documented through the prevalence of diagnoses of asthma, eczema, and hay fever, as well as the annual prevalence of symptoms suggestive of these conditions. Exposure to AAP was estimated using nitrogen oxide concentrations measured by background stations in the Airparif network during pregnancy and modeled using a physicochemical dispersion model for postnatal periods. The association between PAA exposure during different exposure windows and respiratory and allergic morbidity (incidence, prevalence) is examined using various regression models (Cox and logistic), after adjusting for potential confounding factors, with an investigation of moderating effects. Results - This study shows distinct associations with PAA depending on the exposure window and the respiratory/allergic disease under consideration. Postnatal exposure to PAA is linked to allergic respiratory diseases during childhood, whereas prenatal exposure is not. Atopic dermatitis is not associated with PAA exposure. More vulnerable population subgroups are identified, including a parental history of allergy, particularly asthma, early-onset lower respiratory tract infections, and stressful family events that increase susceptibility to the effects of PAA. Conclusion - These results confirm the importance for public authorities to continue efforts to reduce PAA levels in the Paris metropolitan area.