Adolescence is a period of vulnerability to substance use disorders (SUDs). Epidemiological studies indicate that about 23% of Brazilian adolescents use drugs, with alcohol being the most widely consumed substance. The etiology of SUDs is complex, influenced by an interaction of genetic risk, individual development, environmental factors, context of use, and substance used. Clinicians should consider diagnostic criteria and be aware of behavioral changes that may indicate drug use and its consequences in various aspects of adolescent life. Identification and treatment of comorbid conditions is critical to the management of SUDs in this age group. Interventions should restrict access to drugs and facilitate prompt recognition of initial use, preventing progression to serious patterns of abuse or dependence. Intervention should be broad, including academic and occupational activities as well as social relationships and leisure, which are critical to the reestablishment of normal adolescent development.