Despite its uses, the Internet is liable to be abused. “Internet Addiction” is a newly proposed construct, derived form DSM-IV criteria for substance abuse. As a very recent phenomenon, excess internet use probably arises through pre-existing mechanisms. The addictive element may be the search for stimulation through interactive services, or the Internet may serve the purpose of an escape from real-life difficulties. We therefore considered the extent to which sensation seeking or poor self-esteem predicts heavier Internet use. Fifty participants, recruited through the Internet or the Internet Addiction Support Group, completed an Internet Related Problem Scale, the MMPI-2 Addiction Potential Scale, the Coopersmith Self-Esteem Inventory and the Sensation Seeking Scale. The Internet Related Problem Scale showed a moderate level of internal consistency and demonstrated construct validity, predicting hours of Internet use and having a relationship with the Addiction Potential Scale. While poorer self-esteem predicted greater scores on the Internet Related Problem Scale, impulsivity did not. Researchers need to re-assess previous conceptualizations of the typical “computer addict” as a highly educated, male introvert with a constant need for intellectual stimulation (Shotton, 1991).