With alarming frequency, an individual’s first substance use occurs in childhood or adolescence. However, the use of many types of substances among individuals younger than 18 has been gradually declining over the past 6 years, and our understanding of risk factors for youth substance use has improved. Risk factors identified as possibly contributing to a young individual’s first encounter with cigarettes or alcohol include parents’ own substance use or mental health problems. Mental disorders of children have been implicated in substance use as well. Screening and interventions are available to reduce the frequency and intensity of adolescent substance use and are suggested in the current article. Nurses are in a position to identify adolescents who are at risk for substance use disorders and link the family system to effective intervention.