To evaluate computerised cognitive behaviour therapy (CCBT) for the treatment of anxiety, depression, phobias, panic and obsessive-compulsive behaviour (OCD). The software packages to be considered include Beating the Blues (BtB), Overcoming Depression: a five areas approach, FearFighter (FF), Cope and BT Steps. Other packages or programmes incorporating CCBT were also considered.Electronic databases from 1966 to March 2004. Evidence submitted by sponsors for CCBT products.A systematic review was a review of the literature and the evidence submitted by sponsors for each of the products. A series of cost-effectiveness models was developed and run by the project team for the five CCBT products across the three mental health conditions.Twenty studies were identified in the clinical effectiveness review. The analysis of these results showed some evidence that CCBT is as effective as therapist-led cognitive behaviour therapy (TCBT) for the treatment of depression/anxiety and phobia/panic and is more effective than treatment as usual (TAU) in the treatment of depression/anxiety. CCBT also appears to reduce therapist time compared with TCBT. When reviewing cost-effectiveness studies, only one published economic evaluation of CCBT was found. This was an economic evaluation of the depression software BtB alongside a randomised controlled trial (RCT), which found that BtB was cost-effective against TAU in terms of cost per quality-adjusted life-year (QALY) (less than 2000 pounds), however it contained weaknesses that were then addressed in the cost-effectiveness model developed for the study. The results of the model for the depression software packages in terms of incremental cost per QALY compared with TAU and the chance of being cost-effective at 30,000 pounds per QALY were for BtB 1801 pounds and 86.8%, for Cope 7139 pounds and 62.6% and for Overcoming Depression 5391 pounds and 54.4%. The strength of the BtB software being that it has been evaluated in the context of an RCT with a control group. The subgroup analysis found no differences across the severity groupings. For phobia/panic software, the model showed an incremental cost per QALY of FF over relaxation was 2380 pounds. Its position compared with TCBT is less clear. When modelling OCD packages, using the practice-level licence cost meant that BT Steps was dominated by TCBT, which had significantly better outcomes and was cheaper. However, the cheaper PCT licence resulted in the incremental cost-effectiveness of BT Steps over relaxation being 15,581 pounds and TCBT over BT Steps being 22,484 pounds.The study findings are subject to substantial uncertainties around the organisational level for purchasing these products and the likely throughput. This is in addition to concerns with the quality of evidence on response to therapy, longer term outcomes and quality of life. The position of CCBT within a stepped care programme needs to be identified, as well as its relationship to other efforts to increase access to CBT and psychological therapies. Research is needed to compare CCBT with other therapies that reduce therapist time, in particular bibliotherapy and to explore the use of CCBT via the Internet. Independent research is needed, particularly RCTs, that examine areas such as patient preference and therapist involvement within primary care.