The Seasonal Pattern Assessment Questionnaire for Children and Adolescents (SPAQ-CA) is the most frequently used self-report instrument for studying the sensibility to seasonal changes in children and adolescent subjects. The aims of this study were: a) to validate the italian version of the SPAQ-CA; b) to give data about the frequency of seasonality in Italian children and adolescent. The Italian version of SPAQ-CA was administered to a sample of 1709 subjects, aged between 10 and 17 years. This study has shown the good psychometric properties of the italian version of SPAQ-CA (descriptive statistics and internal consistency). Further researches should analyse the SPAQ-CA validity with external criterions. Likewise to how found for the Italian adult population, the incidence of compatible subjects with seasonality is double (8,61%) in comparison to that found in Anglo-Saxon countries. Further searches will have to clarify the role of the potential factors (socio-cultural, environmental, genetic) responsible of such result.