There is increasing concern that the Internet and video games contain an addictive potential. However, it has been discussed, whether pathological Internet use (PIU) is to be diagnosed as an impulse control disorder as pathological gambling or in analogy to substance abuse disorders. Contributing to this discussion, the study compares psychopathological features and co-morbidities of patients with PIU and alcoholism. Methods: Both 25 Internet- and alcohol-dependent patients were assessed for psychopathological symptomatology and co-morbidity with the Structured Clinical Interview according to DSM-IV (SKID), the Symptom-Checklist (SCL-90R), Beck Depression Inventory (BDI), Connors’ Adult ADHD Rating Scales (CAARS) and the Barrat Impulsiveness Scale (BIS).