We aimed to provide process and effectiveness evaluations of a sex education intervention realized with interactive techniques in high schools of Pavia (Italy).

Six public high schools, divided into ‘treated’ and ‘control’ units, voluntarily joined this mixed-methods study. Only second-year classes were enrolled: treated adolescents followed a sex education course, performed by trained ‘near-peer educators’ (undergraduate medical students) with interactive techniques. All adolescents compiled an anonymous effectiveness evaluation questionnaire at baseline (pre-test) and 3 months later (post-test). Sexual knowledge and reported behavioural changes were compared between the two groups through linear mixed-effects models. The process was assessed through a satisfaction questionnaire for treated students, monitoring cards for working group members and cards/diaries for educators.

The final sample consisted of 547 treated and 355 control adolescents (mean age = 15.28 ± 0.61 years). Highly significant changes (p < 0.001) from pre-test to post-test, with strong improvements of treated adolescents, were evident for all knowledge items. No significant changes for behavioural items were reported. Process evaluation showed positive results in adolescents’ satisfaction, highlighting the need for more youth gathering places. Working group members and educators generally provided positive evaluations, although difficult communication was perceived.

The intervention was effective in improving adolescents’ sexual knowledge. The present work highlighted that in Italy sex education in adolescence is still neglected: this could encourage misinformation and health-risk behaviour. Young people perceive the need for a serious health-promoting action in which they could play an active role, spreading educational messages with organized interactive methods.