As evidenced by several trials, cognitive behavior therapy (CBT) is a highly effective treatment for many conditions including panic disorder with or without agoraphobia. However, therapists are short in supply, and patients with conditions like agoraphobia may not seek therapy due to fear of leaving their homes or traveling certain distances. A major challenge therefore is to increase the accessibility and affordability of empirically supported psychological treatments. The results of randomized controlled trails testing Internet delivered self-help programs generally provide evidence to support the continued use and development for a range of conditions. However, there are special treatment aspects that need to be taken into consideration such as internet access and the idiosyncrasies provided in traditional face to face therapies. © 2004 Elsevier Ltd. All rights reserved.