The increasing use of the Internet provides various new opportunities including use within psychiatry. Examples are websites for information, on-line communities for discussion and email communication. A novel promising utility is Internet- or web- based psychological treatments. Clinical trials have shown the efficacy of these foims of treatment, where empirically supported treatments (ESTs) such as cognitive behaviour therapy (CBT) have been adapted to a web- and self-help-based format. Although showing differences in way of presentation as well as in amount and quality of therapist-contact within these studies, they show several similarities. These self-help-based approaches have been shown to be effective in treating panic disorder, phobias, depression, eating disorders, PTSD and social phobia. These are cost effective and supplementary ways of using CBT resources and possibly attractive in various countries where there is a shortage of qualified CBT-therapists. Another area were research is being made is with computer- and Internet-based cognitive training. This course will outline the background and development of Internet- based psychological treatment and rehabilitation as well as present an overview of the research within the area, applied to different diagnosis and clinical problems. Different principles of delivering treatment will be outlined and discussed, including for example text-presentation, degree of program-interactivity as well as degree and form of therapist contact. Based in our experience of setting up an Internet-based treatment for panic disorder at the Psychiatry Centre Karolinska, we will discuss issues of patient selection/ recruitment, web-technology and treatment limitations, as well as presenting clinical impressions of treating patients in this way.