The role of allergic sensitization in chronic sinusitis in childhood is currently unclear, as contrasting results were reported in the studies thus far available. In fact, some surveys found prevalence of atopy up to 60% in subjects with chronic sinusitis, while other failed to confirm any association between the two conditions. The data we obtained in a cross‐sectional study on a large population of children should help in better defining such issue. Among 2200 children referring for evaluation of chronic respiratory symptoms, subjects satisfying at least two of major criteria for the definition of chronic sinusitis were recruited, and underwent to allergen sensitization workup by skin prick test with common inhalant allergens and total IgE measurement. Patients were stratified according to age lower than 3 years (group 1), age between 3 and 6 years (group 2), and age above 6 years (group 3). In all, 351 children (217 boys, 134 girls, mean age 5.23 ± 2.11 years, range 1.5–15 years) were available for evaluation and formed three groups (27 in group 1, 261 in group 2 and 63 in group 3). Prevalence of both sensitization to at least one inhalant allergen by skin test and of high total IgE was 29.9%, with significant difference for the former across age groups, with a value of 7.4% in group 1, 31.4% in group 2 and 33.3% in group 3 (p = 0.028), but after adjusting for age, sinusitis and aeroallergen sensitization were not significantly correlated. The difference across groups for high total IgE did not reach statistical significance, with respective prevalence of 22.7%, 30.1% and 32.1%. It is possible to conclude that the prevalence of sensitization to aeroallergens in children with chronic sinusitis is comparable with that of the general paediatric population, as assessed in the Italian arm of the ISAAC study and this does not account for routine investigation for allergy in children with chronic sinusitis.