Positive Youth Development (PYD) is an approach that promotes resilience and focuses on youth strengths rather than their weaknesses as done by the traditional deficit-based perspective. Research in Europe and North America show that developmental assets are associated with school success, psychological well-being, and lower health risks among youth and young adults. However, not much research has been done on these associations in Latin American contexts. The purpose of this research study is to assess the association between substance use behaviors, such as drunkenness and the use of illicit drugs, and mental health, together with the mediating role of developmental assets representing youth strengths (e.g., social competence) and contextual resources (e.g., social support at home or school). Cross-national data was collected from Colombian (n = 210; 70.4% females) and Peruvian (n = 34...