The Internet is increasingly influential in the lives of adolescents. Although there are many positives, there are also risks related to excessive use and addiction. It is important to recognize clinical signs and symptoms of Internet addiction (compulsive use, withdrawal, tolerance, and adverse consequences), treat comorbid conditions (other substance use disorders, attention deficit hyperactivity disorder, anxiety, depression, and hostility), and initiate psychosocial interventions. More research on this topic will help to provide consensus on diagnostic criteria and further clarify optimal management.