Impulse-control disorders have received relatively little attention from the mental health community. An increasing awareness of the prevalence and impact of these disorders is emerging. Among impulse-control disorders, problematic Internet use has been considered and examined. Prevalence estimate studies indicate that problematic Internet use is experienced across geographic locations by many individuals of diverse backgrounds. This review examines problematic Internet use from epidemiological and clinical perspectives. Clinicians should be familiar with the extent of problematic Internet use and the data regarding the efficacies and tolerabilities of available treatments.