Since the mid-1990s, there have been frequent reports of individuals whose use of the computer and internet is problematic. Given the recent expansion and the expected increase in internet availability and usage in the coming years, it is important that healthcare professionals be informed about this behavior and its associated problems. Recently, psychological and psychiatric literature has described individuals that exhibit problematic internet use who often suffer from other psychiatric disorders. In the face of this comorbidity, it is essential to evaluate whether these individuals represent a distinct class of disorder, or a manifestation/coping mechanism related to other underlying diagnosis. In either event, problematic internet use negatively impacts social and emotional functioning. Based on the current limited empirical evidence, problematic internet use may best be classified as an impulse control disorder. It is therefore imperative that problematic internet use be appropriately identified among symptomatic individuals. For these reasons, we propose specific diagnostic criteria that will allow for consistent identification and assist in further study of this behavior.