Suicide is a major public health concern, which disproportionally affects young people. Therefore, effective prevention strategies are needed, but there is a dearth of controlled trials on this topic. Our study will evaluate the effectiveness of a suicide prevention program in Switzerland, where data are scarce. It will test whether the prevention program (1) increases knowledge of suicide and awareness of suicidal risks, (2) provides resources to seek/offer help, (3) increases communication skills related to suicide, (4) increases coping skills, (5) is acceptable, and (6) reduces suicidal ideation and psychological distress. The project will be a single-center cluster non-randomized controlled trial designed to compare an intervention group benefitting from the suicide prevention program with a control group. The potential benefits include a better understanding and evaluation of suicide prevention programs, which may lead to improved primary and secondary prevention practices.