Health literacy was identified as an important determinant of health, particularly for adolescents. However, more efforts are needed to monitor this construct and provide inputs for policy development. This study aims to: (a) Assess the validity and reliability of the Italian version of the Health Literacy for School-Aged Children (HLSAC-I); (b) Identify the health literacy levels among Italian students and compare them with other countries' levels; and (c) Identify the associations between health literacy and multiple social determinants (social stratifiers, family, and school connectedness). Data came from the Health Behaviour School-Aged Children survey, carried out in the Lombardy region in northern Italy in 2018. A representative sample of 2,287 13- and 15-year-old Lombardian students was involved. The results support the validity and reliability of the HLSAC-I. A total of 18.7% of the sample reported low levels, and only 6.8% reported high levels. Italian students reported the lowest levels of health literacy compared with other countries. School connectedness and educational approach are the most relevant associated factors. This study confirms a school's role in reducing inequalities and promoting health. It highlights the importance of monitoring health literacy and implementing health promotion policies at school through a whole-school approach.
Keywords: adolescent; family support; health literacy; health promotion; measurement; school health; school support; school-aged children.