The Internet, including modern information technology, has had a dramatic impact on many areas of life, including health care and psychological treatment. In particular, cognitive–behavioral therapy (CBT) has been found to be a form of psychological treatment that has been possible to transfer to other modes of delivery than regular face-to-face and group formats. The Internet is not only useful for providing CBT, but has a significant role in providing information about CBT and conditions that are treated using CBT. In addition, modern information technology also has a major role in assessment procedures, such as online administration of self-report mea- sures. In this article, we focus mainly on Internet-supported treatments, although another emerging format is to use video conferencing systems and conduct real- time face-to-face CBT, CBT training, or supervision.