"Truancy is a serious public health problem that affects adolescents from all countries around the world. In the United States, it has been reported that up to 35% of high school students skipped one or more days of school during a school year. However, little is known on the short- and long-term outcomes of underlying psychological and mental ill-health for those adolescents who truant. Research has indicated that truancy has severe and far reaching consequences, such as maladjustment, substance abuse, delinquency and crime. Most studies, performed in the USA, proposed mechanistic and law-enforcement interventions to prevent truancy. However this approach doesn’t take in consideration the psychological distress that is associated with this phenomenon and may even have negative consequences on adolescents’ well-being and mental health. The main objectives of the WE-STAY (Working in Europe to Stop Truancy among Youth) project are to gather epidemiological information on truancy on European adolescents; to perform intervention school-based programmes for adolescents, aimed at reducing truancy rates and improve mental health of students; to evaluate outcomes of the interventions, in comparison with a control group, from a multidisciplinary perspective including social, psychological and economical aspects; to recommend effective, culturally adjusted models for preventing truancy and promoting mental health of adolescents in different European countries. The WE-STAY project proposes to implement and evaluate outcomes of three different kinds of intervention against truancy: a) a universal intervention based on an awareness program for students, teachers and parents; b) a screening intervention aimed at identifying students at risk and refer them to mental health services; c) a combination of the above interventions. A mechanistic intervention to stop truancy will be used as control."